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8. Contributors

Author

Abel, Dori, Abelman, Rebecca A., Abu Kar, Sarah, Abughazaleh, Saeed, Abu-Nejim, Husam, Afari, Maxwell Eyram, Ahmed, Hammood, Akoto, Shanice, Alabre, Kenneth, Ali, Fahad, Ali, Tanya, Alipanah-Lechner, Narges, Altunel, Erdem, Alzoebie, Lama, Anderson, Chelsie, Andrews, Christine B., Anthony, AnnGene, Arcand, Paul-Hugo, Arora, Sohrab, Asaro, Joseph A., Astashchanka, Anna, Atchison, Douglas, Aulakh, Sudeep K., Aurora, Taruna, Avasare, Rupali, Babadi, Baktash, Babar, Tania B., Bachman, Emelia Argyropoulos, Bains, Ashika, Balabanov, Roumen, Balaguera, Pedro, Balda, Javier, Bank, T. Caroline, Banwell, Brenda, Barrera, Francisco J., Barta, Samantha, Basman, Craig L., Bass, Crystal T., Beach, Scott R., Bediako, Persey, Belcher, Ren, Bell, Jennifer, Bellinghausen, Amy L., Bennett, Colleen E., Berkowitz, Carol D., Betageri, Omkar, Bharmal, Murtaza, Bhatt, Harikrashna B., Bhuptani, Prachi H., Bido-Medina, Richard O., Bielak, Kendall, Bilodeau, Courtney Clark, Bird, Lisa, Bishop, Erin, Bitar, Ghamar, Blakeney, Craig, Blatz, Allison M., Block, Brian, Bortz, Christina M., Bosse, Kristopher R., Bouton, Tara C., Bove, Mary E., Bowlby, Lynn A., Boyden, Sean, Brady, Mark F., Braide, Biobele, Brar, Jessica K., Bratman, Russell E., Brodowsky, Emily Chan, Brown, Austin K., Brown, Emily C.B., Brugnoni, Jessalyn, Bui, Eric, Burke, Christine, Burton, Lauren, Butler, Blythe, Butler, William, Byanova, Katerina L., Byg, Blaire, Callanan, Tucker C., Cantos, Adriana, Canty, Katherine W., Carragee, Eugene, Carrel-Lammert, Meredith, Castillo, Jorge J., Chait, Daniel, Chan, Philip A., Chapman, Arlene, Chatterjee-Paer, Sudeshna, Cheng, Vicky, Chien, Michael, Chilcote, Jeffrey, II, Childs, Candicee, Chopra, Amit, Chou, Stella T., Choudhury, Natasha, Christian, Cindy W., Chua, Winona, Chun, Andrew S., Claman, David, Clark, Grace V., Clark, Seth, Clarke, Ross, Clay, Alexandra, Clebak, Karl T., Cleland, Derrick, Cohen, Debbie L., Cohen, Lisa, Congdon, Morgan, Constantinou, Maria, Cooper, James Elliott, Corley, James Earl, Cosgrove, Abigail, Covarrubias, Oscar, Craine, Rebecca, Criddle, Sarah, Cristofaro, Patricia, Cunha, Joanne Szczygiel, Cunningham, Karlene, Cusano, Joseph, D’Alessandro, Frank B., Dado, Lynn, Daneshdoost, Shanaz, Daneshvari, Nicholas Omid, Darwiche, Sabrina, Das, Abhijit, DaSilva, Manuel F., De La Garza, Carlos, DeDent, Alison, Deeb, Mery, Denninger, John W., Desrochers, Colette, Devon, Erin Pete, Diaz, Joseph A., DiGrande, Kyle, Dina, Ayodeji, Doo, Kathleen, Drury, Brian, Dus, Bethany, Dutta, Roop, Dworkin, Myles, Dyster, Timothy G., Ebert, Eric, Edmund, Joseph, Edward, Heather L., Eggers, Erica, Eisenhower, Christine, Ellsworth, Pamela, Elnair, Radowan, Escamilla-Ocañas, César E., Espinosa, Patricio Sebastian, Faber, Mark D., Facer, Evan, Fadale, Paul D., Fallon, Ryan T., Farias, Michael J., Farkas, Jon, Farrand, Erica, Farrell, Ronan, Fay, Kevin S., Fender, Robert Zachary, Hernandez, Samantha Fernandez, Fernandez-Robles, Carlos, Ferreira, Jason D., Ferri, Fred F., Ferri, Heather, Fields, Jessica C., Fields, Lauren, Fischer, Staci A., Fiske, Hannah, Florez, Maria Camila Velez, Forbes, Kellie C., Forcier, Michelle, Ford, Sydney, Fort, Frank G., Fort, Glenn G., Frankel, Eitan S., Freeman, Nancy, Friedman, Ryan, Frisch, Daniel R., Fru, Relindis Azenwi, Fullenkamp, Lynn C., Gaffney, Michael, Garcia, Jose P., Garcia, Paloma Jolin, Ge, Jonathan S., Gesthalter, Yaron B., Ghimire, Anil, Gibson, Christopher, Gidwani, Nisha H., Gilek-Seibert, Katarzyna, Gilvaz, Vinit J., Glueck, Jacob, Goetz, Jennifer Leah, Goldburt, Alla, Goldsmith, Corey Elam, Rao Golla, Maheswara Satya Gangadhara, Gomez, Alexander, Slagle, Helen B. Gomez, Greenblatt, H. Karl, Greenfield, Morgan, Gugerty, Lindsay, Gultawatvichai, Patan, Gunning, Samantha, Guo, David, Gupta, Simran, Guttadauria, Brittany, Gwinn, Meghan, Hadi, Mohanad, Hafeez, Muhammad Ubaid, Hall, Hayden, Hall, Sarah, Handa, Sajeev, Hanna, John R., Harbord, Nikolas, Hardacker, Kyle, Hardesty, Anna, Haribhakti, Nirav, Harris, Daniel J., Hartmann, Abigail, Hartnett, Davis A., Hartvigsen, Nathan, Hawkins, Brian, He, Elaine, Heinle, Rachel Wright, Helm, Leesha A., Helm, Matthew F., Herlevich, Thomas, Hermez, Klodia M., Hilliard, Ross W., Hocker, Nathaniel, Hoffman, R. Scott, Holton, Siri M., Homer, Alexander S., Hook, Benjamin E., Hsu, Raymond, Huang, Laurence, Hull, Mariam, Hume, Anne L., Hussain, Zilla, Huynh, Donny V., Hyder, Sarah, Ingraham, Caitlin, Insalaco, Louis F., Jackson, James, Jafari-Esfahani, Shadi, Jain, Rishubh, Jain, Vanita B.D., Jain, Vipul V., Jamal, Fariha, Janigian, Robert H., Jr., Jasuja, Sonia, Javier, Noelle Marie, Jayachandran, Nishant, Jetty, Vybhav, Johnson, Michael P., Johnson, Steven D., Jones, Amanda, Joseph, Tatiana, Joseph-Senatus, Ganaelle, Joshi, Shyam, Justice, Joshua, Kabashneh, Sohaip, Kadiyala, Vishnu, Kalligeros, Markos, Karthikeyan, Vanji, Kaske, Erika, Kasper, Vania, Kass, Joseph S., Kass, Naomi R., Kasthuri, Viknesh S., Katz, Luca, Kazakova, Vera, Keim, Jennifer L., Kensey, Nicholas, Kent, Victoria, Kerrigan, Danielle, Keselman, Dennis, Khare, Sarthak, Khatri, Surya, Khawaja, Hussain R., Khurana, Saranya S., Kifle, Betelhem, Kim, Chan Woo, Kim, Jinseong, Kisare, Samantha, Kohrman, Samuel I., Kokkirala, Aravind Rao, Konstantino, Yuval, Kontos, Nicholas, Kopyt, Nelson, Kothadia, Savan, Koti, Ajay S., Koulouridis, Ioannis, Kreider, Timothy R., Kron, Kevin, Krumm, Ilana, Kuhn, Elizabeth, Kumbar, Lalathaksha, Kuo, Sheng-Han, Kuris, Eren O., Kurss, David I., Kutschke, Michael J., Laband, William F., LaCombe, Philip, Lam, Uyen T., Lam, Wilson, Laredo, Jonathan, Larijani, Mary, Le, Peter, Leahy, Caroline, Leard, Lorriana E., Leavitt, David A., Leba, Christopher T., Lee, Hyung Jin, Lee, Kachiu C., LeGros, Tracy Leigh, Lemme, Nicholas J., L’Etoile, Nathan, Li, Jian, Lim, Carol, Lin, Chi-Ying (Roy), Lippincott, Jordan, Liu, Jonathan, Logue, Teresa C., Longtain, Riley, López, Gabriela, Lord, Kito Akin, Loscalzo, Kirsten, Lucas, Mathew J., Lucier, David J., Jr., Ma’ayeh, Marwan, MacLean, Rachel L., MacMurdo, Maeve G., Madva, Elizabeth N., Maher, Lewena, Makai, Gretchen, Malpica, Luis, Marks, Jonathan, Pinheiro, Ana Paula Marques, Marr, Mollie C., Martinez, Adali, Matin, Adiba, Mazzaglia, Peter J., Mbuyi, Nadine N., McCulloh, Russell J., McDonald-McGinn, Donna M., McGowen, Alexandra, McGraw, Katherine Elizabeth, McKenna, Jaclyn, McNamara, Kelly, Meleveedu, Kapil S., Mendez-Miller, Megan, Mercado, Jorge, Mercado, Osvaldo, Merritt, Rory, Michaels, Marian G., Michel, Jeremy, Mikolasko, Brian D., Milner, John D., Min, May, Minami, Taro, Mohamed, Mouhand F., Najjar-Mojarrab, Javad, Molinari, John, Montgrain, Philippe, Moon, Heesung, Moore, Michael Z., Moore, Shawn D., Morelli, Leah, Morrissey, Patrick J., Mughal, Aleem I., Mukkamalla, Shiva Kumar R., Mullen, Marguerite A., Mulliken, Alexandra, Mumtaz, Tayebah, Muraina, Fadeke, Mustafa, Ahmad, Myers, Ellen, Mylhousen, Emily, Nadaud, Jack, Nadella, Akash, Nadella, Mohnish, Nadjarian, Albert, Nagpal, Nikita, Nathan, Miriam, Naveed, Asim, Nawaiseh, Ahmad Al, Neff, Robert, Neithardt, Adrienne B., Nestlerode, Christina, Niazi, Azfar K., Nisavic, Mladen, Nokoff, Natalie, Noorbhai, Ibrahim Z.D., Novak, James E., Novarra, Austin, John, Audrey R. Odom, Okewunmi, Jeffrey, Oliver, Rebecca, Olszewski, Adam J., Onyeaka, Henry K., Orchowski, Lindsay M., Osorio, Marcela, Osorio, Luis, O’Sullivan, Cassidy, Outlaw, Jasmine, Oyelakin, Ayotomide, Pace, Paolo G., Paddock, John E., Painter, David F., Palmieri, Alicia, Pappas-Taffer, Lisa, Paranandi, Sneha, Parikh, Mihir, Partin, Michael T., Patel, Birju B., Patel, Melissa D., Patel, Minta, Patel, Nima R., Patel, Pranav M., Patel, Vishal I., Patrick, Brett, Paudel, Shreedhar, Pelcovits, Ari, Perez, David L., Perez, Jose J. Hermina, Pétron, Clément, Pfeuti, Courtney, Pham, Lily C., Phillips, Katharine A., Phillips, Oliver W., Phillips, Tara M., Piana, Lauren E., Portnoff, Brandon S., Pou, Sovijja, Prashar, Rohini, Pulice, Christine, Punko, Diana, Purkayastha, Ayan, Qawi, Imrana, Qu, David, Quesada, Adrian, Quinn, Matthew S., Racchi, Nicholas, Rachu, Gregory S., Rajadurai, Suvithan, Ramachandran, Lintu, Rana, Tanvi, Rathore, Bharti, Rathore, Ritesh, Raukar, Neha P., Ravindra, Lakshmi, Reagan, John L., Reardon, P.K., Reddy, Bharathi V., Reddy, Snigdha T., Reed-Weston, Anne, Reginato, Anthony M., Reichart, James P., Reus, Victor I., Reuter, Matthew, Riaz, Sana, Ricci, Brittany, Rich, Harlan G., Richter, Savanah, Rivera, Lauren Davis, Robertson, Melena J., Roby, Lauren C., Roche, Meaghan, Rodriguez, Alejandra E. Morfin, Gómez, Perla M. Romero, Ron, Hayley A., Rossi, Michael, Rubin, David, Rubin, Lila, Rushworth, Parker, Rutstein, Beth H., Sadeghi, Noushine, Sahota, Ruchi Jalota, Saks, Emily, Sall, Jeffrey W., Salvi, Joshua D., Sanchez, Frank A., Sanchez, Martha C., Sanka, Pranavi, Santhosh, Lekshmi, Santos, Linda Herrera, Sauck, Emily, Saylor, Leah, Scheuing, William J., Sciscione, Anthony, Scott, Matthew Thomas, Sederdahl, Bethany K., Seeber, Richard E., II, Sellers, Kyle, Sen, Aritra, Sewell, Rachel, Shaban, Hesham, Shah, Ankur, Shah, Isha, Shakil, Omair, Sharma, Animesh, Sharma, Yuvraj, Sharp, Lydia, Sherman, Alexander, Shill, Jessica E., Shimanovsky, Alexei, Shipp, Michael M., Shlossman, Philip A., Siddiqui, Khawja A., Siegel, Alyssa, Sigman, Mark, Singh, Harinder P., Singh, Jasneet, Singh, Manjot, Slingsby, Brett, Sloane, Amy J., Smick, Alexandra H., Smith, Jeanette G., Smith, Matthew J., Sohaney, Ryann, Soi, Vivek, Soinski, Rebecca, Soler, Maria E., Soman, Sandeep, Sorg, Emily, Sosnoski, Olivia, Sperati, C. John, Stanford, Nathan, Steele, Emery, Steele, Jacqueline, Stern, Ella, Stier, James, Stockwell, Philip, Subramanian, Lakshmi, Suen, Angela, Suh, Edward, Sundaramoorthy, Anjali, Sunkara, Naveena, Supanakorn, Varut, Suri, Priyasha, Sweeney, Hannah, Takasaki, Kaoru, Takei, Ryosuke, Tan, Laren, Tarawneh, Mohammad, Taylor, Alan, Taylor, Kathryn Marie, Taylor, Matthew A., Taylor, S. Trevor, Tenney-Soeiro, Rebecca, Thomas, Anthony G., Thompson, Stefani, Tien, Alexandra Meyer, Tien, David Robbins, Tierney, Anna-Marie, Toma, Helen, Lopez, Kim Tran, Tryforos, Margaret, Tsaban, Gal, Tschoe, Christine, Tungate, Robert, Turn, Christina S., Uduman, Junior, Umanath, Kausik, Ungar, Stephanie P., Vakili, Babak, van Deventer, Ella, Vemula, Ridhima, Venado, Aida, Vollum, Kathryn G., Vorel, Ethan, Walson, Ifeanyi, Wang, Angela, Wang, Emily, Wang, Li, Wehner, Linsey, Westreich, Roi, Wheeler, Ericka, Wighton, Nakia, Wildman, Alexis, Wilson, Annise, Winikor, Jared M., Wininger, Bryce, Winschel, Julia M., Wold, Jaclyn, Wolpaw, Adam J., Wolpert, Marlene Fishman, Wong, Elisabeth A., Wylie, John, Yang, Anna, Yao, Xuan, Yesodharan, Gemini, Yeung, Jennifer, Yin, Chun H., Yip, Agustin G., Yu, Diana H., Yu, Elizabeth An, Yung, Jeffrey, Zainelabdin, Sarah, Zambrano, Juliana, Zargarian, Emin, Zha, B. Shoshana, Zhang, Helen, Zhao, Leon, Zhou, Diana X., Ziaie, Navid, and Zorin, Danylo

Published
2025
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12. On the MIMO Capacity With Joint Sum and Per-Antenna Power Constraints: A New Efficient Numerical Method.

Author

Pham, Thuy M., Farrell, Ronan, Claussen, Holger, Flanagan, Mark F., and Tran, Le-Nam

Subjects
*GAUSSIAN channels, *MISO, *COLUMNS, *SIGNAL-to-noise ratio
Abstract

We propose a semi-closed-form solution to the problem of computing the capacity and optimal signaling for a Gaussian MIMO channel under a joint sum power constraint (SPC) and per-antenna power constraint (PAPC). Existing efficient solutions to this fundamental problem are only applicable to some special cases: multiple-input single-output (MISO) systems, or full column rank MIMO channels with sufficiently high transmit power, or full-rank optimal signaling. For the general case, we present an efficient numerical method to solve the considered problem which does not make any assumptions on the rank of the channel matrix or the maximum transmit power. To achieve this, the considered problem is transformed into an equivalent minimax problem. We then exploit the special structure of the minimax problem to derive a closed-form solution based on a concave-convex procedure (CCP)-like algorithm. Extensive simulation results show that our proposed algorithm outperforms the existing solutions in terms of complexity and generality. [ABSTRACT FROM AUTHOR]

Published
2022
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17. Phase-Only Digital Predistortion Technique for Class-E Outphasing Power Amplifiers

Author

Afanasyev, Pavel, Ramabadran, Prasidh, Mohammady, Somayeh, Farrell, Ronan, and Dooley, John

Abstract

Efficient and linear power amplifiers (PA) are an essential part of forthcoming 5G wireless systems. Outphasing class-E PAs offer high power efficiency and an option for higher efficiency cellular networks. However, they employ signal component separators, which split the signal into two paths. In order to efficiently recombine the signal, nonlinear power combiners are used. This paper proposes a novel phase-only predistortion technique for outphasing class-E PAs. The predistortion coefficients can be extracted based on AMAM characteristics of the output signal and an analytical model of an outphasing Class E PA. The suggested technique has been validated by simulation of an outphasing power amplifier in ADS Ptolemy software. It is shown that applying this technique to a 16QAM OFDM modulated signal with 20 MHz bandwidth improves error vector magnitude (EVM) from 10.39% to 2.43% compared to the signal without predistortion.

Published
2019

18. Contributors

Author

Abbott, Jinnette Dawn, Agarwal, Rajiv, Al-Badri, Marwa, Ryoo Ali, Hyeon-Ju, Aliotta, Jason M., Almhanna, Khaldoun, Al-Qaisi, Mohanad T., Arzomand, Zuhal, Asombang, Akwi W., Aung, Su N., Azzoli, Christopher G., Bandera, Christina, Banerjee, Debasree, Batheja, Mashal, Bazarian, Jeffrey J., Benbadis, Selim R., Benjamin, Ivor J., Benoit, Eric, Berger, Marcie G., Bergwitz, Clemens, Berliner, Nancy, Berns, Jeffrey S., Bhadbhade, Pooja, Bhavaraju-Sanka, Ratna, Bichile, Tanmayee, Birnbaum, Ariel E., Bliss, Charles M., Jr, Blum, Andrew S., Bonder, Bryan J., Bratman, Russell, Braunstein, Glenn D., Guerrero Bready, Alma M., Bungiro, Richard, Burgner, Anna Marie, Cahill, Jonathan, Canakis, Andrew, Carneiro, Benedito A., Casserly, Brian, Chahin, Abdullah, Chan, Philip A., Chapin, Kimberle, Cheshire, William P., Jr., Chung, Waihong, Ciafaloni, Emma, Cigarroa, Joaquin E., Cinquegrani, Michael P., Coca, Andreea, Cohen, Harvey Jay, Cohen, Scott, Concepcion, Beatrice P., Connell, Nathan T., Constantinou, Maria, Cortez, Roberto, Counihan, Timothy J., Cross, Anne Haney, Cunha, Cheston B., Cunha, Joanne S., Cu-Uvin, Susan, Dabbouseh, Noura M., Dapaah-Afriyie, Kwame, Denney-Koelsch, Erin M., De Souza, Andre, De Vriese, An S., Dharmadhikari, Neal D., Dickstein, Leah, Dizon, Don, Domsic, Robyn T., Eagle, Kim A., Earing, Michael G., Egan, Pamela, El-Deiry, Wafik S., Elkind, Mitchell S.V., Evans, Tarra B., Fallon, Michael B., Farmakiotis, Dimitrios, Farraye, Francis A., Farrell, Ronan, Fasseas, Panayotis, Fenton, Mary Anne, Fervenza, Fernando C., Fine, Sean, Finn, Arkadiy, Flanigan, Timothy, Flores, Brisas M., Foderaro, Andrew E., Friedman, Theodore C., Garland, Joseph Metmowlee, Gartman, Eric J., Geara, Abdallah, Gil, Raul Macias, Gilligan, Timothy, Goggins, Michael Raymond, Gopalakrishnan, Geetha, Gopinath, Vidya, Greenspan, Susan L., Hamdy, Osama, Hamel, Johanna, Handa, Sajeev, Heflin, Mitchell T., Holloway, Robert G., Huang, Christopher S., Hussain, Zilla, Ikizler, T. Alp, Isufi, Iris, Jackson, Carlayne E., Jacob, Paul G., Jankowich, Matthew D., Johnsen, Niels V., Johnson, Jessica E., June, Rayford R., Kheirbek, Tareq, Khorana, Alok A., Kilic, Sena, Kim, David, Kleczka, James, Klinger, James R., Koo, Patrick, Koolwal, Pooja, Kotlarczyk, Mary P., Kuderer, Nicole M., Kwara, Awewura, Kwon, Jennifer M., Lange, Richard A., Larkin, Jerome, Lee, Alfred I., Levine, Daniel J., Lewandowski, David E., Liang, Kelly V., Liang, Kimberly P., Lichtenstein, David R., Lienesch, Douglas W., Ling, Geoffrey S.F., Little, Ester, Liu, Yi, Lohr, Nicole L., Lonks, John R., Lyman, Gary H., Lyness, Jeffrey M., Lyons, Shane, Maas, Diana, Malik, Talha A., Manocha, Sonia, Manzi, Susan, Marshall, Frederick J., McCool, F. Dennis, McCulloh, Russell J., McGarry, Kelly, Govern, Eavan Mc, McKinney, Robin L., Mega, Anthony, Mehta, Shivang, Milam, Douglas F., Mileno, Maria D., Misra, Abhinav Kumar, Moe, Orson W., Mohan, Niveditha, Moreland, Larry W., Morrison, Alan R., Moss, Steven F., Mullin, Christopher J., Murphy, Sinéad M., Nallu, Sagarika, Neyra, Javier A., Noaiseh, Ghaith, Ollila, Thomas A., Opal, Steven M., Palmer, Biff F., Pan, Jen Jung, Papazoglou, Anna, Parnes, Aric, Patel, Nayan M., Pelcovits, Ari, Perazella, Mark A., Picco, Michael F., Powers, Kate E., Previll, Laura A., Rajora, Nilum, Ramirez-Zamora, Adolfo, Reagan, John, Reece, Rebecca, Rich, Harlan, Richman, Jennifer H., Rogers, Lisa R., Rogers, Ralph, Rose, Michal G., Roth, James A., Rounds, Sharon, Rubenstein, Jason C., Rupawala, Abbas, Sarvaideo, Jenna, Saxena, Ramesh, Schiffman, Fred J., Schneider, Ruth B., Seaborg, Kristin A., Seetharam, Anil, Seropian, Stuart, Sethi, Jigme Michael, Sethi, Sanjeev, Shane, Elizabeth, Sharma, Esseim, Shastri, Shani, Shea, Barry S., Shevell, Lauren, Smith, Joseph A., Jr., Smith, Robert J., Sohal, Davendra P.S., Song, Christopher, Sperry, Thomas, Statland, Jeffrey M., Stein, Emily M., Strande, Jennifer L., Strenger, Rochelle, Talbot, Thomas R., Tarolli, Christopher G., Tarshish, Yael, Taunk, Pushpak, Tsoukas, Philip, Tunkel, Allan R., Turner, Jeffrey M., Vazquez, Zoe G.S., Vela, Stacie A.F., Vespa, Paul M., Vongpatanasin, Wanpen, Walker, Marcella D., Wang, Eunice S., Wasan, Sharmeel K., Weber, Thomas J., Wilcoxson, Brandon J., Wing, Edward J., Wong, Ellice, Wysolmerski, John J., Yousefzai, Rayan, Ziegler, Thomas R., and Zon, Rebecca

Published
2022
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19. A low complexity pre-distortion scheme for power amplifier linearization in wideband applications

Author

Varahram, Pooria, Dooley, John, Finnerty, Keith, and Farrell, Ronan

Abstract

In this paper, a nonlinear autoregressive with exogenous inputs (NARX) digital pre-distortion scheme to linearize power amplifiers is proposed. The proposed NARX digital pre-distortion gives better accuracy and spectral leakage suppression compared with other commonly used Volterra-based techniques. The stability criterion of the NARX digital pre-distortion is derived from the frequency domain analysis. Simulation is carried out with a 20MHz single carrier long-term evolution signal and two-carrier long-term evolution signal and instantaneous to average ratio of 6.2dB at 0.01% complementary cumulative distribution function (CCDF). The results ofsimulation analysisshow aslightimprovementin adjacent channelleakageratio performance with 30% reduction in the number of floating point operations compared with conventional predistortion techniques.

Published
2017

20. A Low Complexity NARX Structure using Indirect Learning Architecture for Digital Pre-Distortion

Author

Varahram, Pooria, Dooley, John, Wang, Ziming, Finnerty, Keith, and Farrell, Ronan

Abstract

In this paper, we demonstrate a nonlinear autoregressive with exogenous input (NARX) DPD technique which is more compact, less computationally intensive and less susceptible to errors caused by noise in the PA output compared to an equivalent memory polynomial based DPD. Experimental validation is performed with a 20 MHz LTE signal for a GaN Doherty power amplifier.

Published
2017

21. Frequency Interleaved Modulators to Support Channel Bonding in Satellite Communications

Author

Ramabadran, Prasidh, Dooley, John, and Farrell, Ronan

Abstract

Next generation wireless communication systems such as high throughput satellites and fifth generation mobile communications have promised a step increase in the rate at which data can be transmitted. This would ideally require bespoke modulator designs for the ground stations with wide bandwidths employing expensive high throughput data converters. The next generation communications hardware also need to be backward compatible with legacy systems of lower bandwidths till they are rendered obsolete. In this paper we demonstrate a scheme to generate a wide bandwidth modulated baseband signal with multiple modulators of narrower bandwidths in a satellite communications ground station.

Published
2017

22. Contributors

Author

Abrams-Downey, Alexandra, Adkins, W. Peyton, Afari, Maxwell Eyram, Agarwal, Sandeep, Al Jandali, Mhd Hussam, Alhudairy, Maad M., Ali, Tanya, Allen, Stephanie Michelle, Alomari, Ihab, Alqadi, Rasha B., Anderson, Jordan, Andrievskaya, Maria, Anilowski, Kathryn Taylor, Anthony, Anngene, Aoun, Joe, Argueta, Erick A., Arikan, Pinar, Arzomand, Zuhal, Asiedu, Daniel K., Aulakh, Sudeep K., Avasare, Rupali, Aziz, Sarah, Babar, Tania B., Bachman, Emelia Argyropoulos, Bank, T. Caroline, Barrett, Trace, Barseghian, Ailin, Basman, Craig L., Baumgarten, Lee, Bell, Jennifer, Benner, Deanna, Bergen, Michael, Berges, Arnaldo A., Bhagat, Vicky H., Bhatt, Harikrashna B., Bhatti, Danish, Bi, Jiaying, Bilodeau, Courtney Clark, Bissonette, Stefani, Bitar, Ghamar, Blakeney, Craig, Blankenhorn, Brad, Blomberg, Christopher P., Bokshan, Steven L., Borchert, Alex F., Bortz, Christina M., Boske, Alexandra, Bouton, Tara C., Bowlby, Lynn A., Box, Amanda, Brady, Mark F., Bratman, Russell E., Brennan, Keith, Brown, Gavin, Bucher, Neal, Buckley, Jennifer, Buffie, Alexandra, Burke, Christine, Burris, Ryan J.W., Burtis, D.Brandon, Cahill, Kate, Cangemi, Rebecca, Cantrell, Caleb, Caraganis, Andrew, Carter, Ashlie Sewdass, Carter, Valerie, Castaneda-Guarderas, Ana, Castillo, Jorge J., Catana, Andreea M., Cerezo, Carolina S., Chalkely, Joshua, Chamberlain, Paul D., Chan, Philip A., Chawla, Anjulika, Chen, Dhruti P., Cheng, Vicky, Chis, Roxana, Chisholm, Sarah L., Chitturi, Chandrika, Cholankeril, George, Cholankeril, Rosann, Clark, Seth, Clyne, Brian, Cohen, Debbie L., Cohen, Lisa, Cohn, Zachary, Congrete, Soontharee, Cook, River, Copelin, Eddie L., II, Corley, James Earl, III, Craine, Rebecca, Cramer, Meagan S., Cristofaro, Patricia, Crouss, Tess, Cunha, Joanne Szczygiel, Cunningham, Karlene, Curtin, Alicia J., Dabiri, Ganary, Dado, Lynn, Dalal, Deepan S., Dalphon, Kristin, Dalrymple, Kristy L., Daly, Gerard H., Danak, Shivang U., Das, Rituparna, DaSilva, Manuel F., D’Avanzato, Catherine, DeFroda, Steven F., Degenhardt, Alexandra, Dhokte, Ashwini U., Diaz, Joseph A., Dillon, Allison, Dohlman, Thomas H., Dolter, Stephen, Domenichini, David J., Doo, Kathleen, Dove, James H., Duker, Andrew P., Dwivedi, Shashank, Eickhoff, Evlyn, Eisenhower, Christine, Elghafri, Amani A., Ellsworth, Pamela, Epstein, Alan, Espinosa, Patricio Sebastian, Evans, Danyelle, Faber, Mark D., Fagan, Matthew J., Farrell, Ronan, Farrell, Timothy W., Fay, Kevin, Fayek, Mariam, Ferreira, Jason D., Ferri, Fred F., Ferri, Heather, Fine, Barry, Fischer, Staci A., Fong, Tamara G., Fonge, Yaneve, Forcier, Michelle, Fort, Frank G., Fort, Glenn G., Fraser, Justin F., Fricchione, Gregory L., Friedman, Michael, Frisch, Daniel R., Gallo, Anthony, Ghanim, Mostafa, Ghobrial, Irene M., Gilek-Seibert, Katarzyna, Gillerman, Richard, Gillis-Smith, Andrew, Gitelmaker, Dimitri, Goldburt, Alla, Goldfarb, Danielle, Goldman, Jesse, Goldsmith, Corey, Gangadhara Rao Golla, Maheswara Satya, Golski, Caroline, Gomez, Helen B., Goodman, Avi D., Gordon, Paul, Gray, John A., Gringut, Simon, Grocott, Lauren, Grupke, Stephen L., Guerra, Juan, Gultawatvichai, Patan, Guo, David, Gupta, Priya Sarin, Hack, Nawaz K.A., Haim, Moti, Handa, Sajeev, Hanif, M. Owais, Harbord, Nikolas, Harchandani, Sonali, Hardy, Erica, Harrington, Colin J., Harrison, Taylor, Hawkins, Brian, Hayes, Don, Jr., Hegde, Shruti, Heinle, Rachel Wright, Heitmiller, Dwayne R., Herek, Jyothsna I., Hines, Margaret R., Hodges, Ashley, Hoffman, Pamela E., Hoffman, R. Scott, Hogan, Dawn, Holland, N. Wilson, Holton, Siri M., Hume, Anne L., Hussain, Zilla, Huynh, Donny V., Huynh, Terri Q., Hyder, Sarah, Ibrahim, Dina A., Ingraham, Caitlin, Inman, Nicholas J., Insalaco, Louis, Jacobson, Ashley A., Jain, Koyal, Jain, Vanita D., Jamal, Fariha, Jamot, Sehrish, Janigian, Robert H., Jr., Javier, Noelle Marie, Johl, Michael, Johnson, Christina M., Johnson, Michael P., Jolly, Angad, Jonas, Rebecca, Jones, Kimberly, Joshi, Shyam, Kapoor, Siddharth, Karthikeyan, Vanji, Kass, Joseph S., Katz, Emily R., Kazim, Ali, Kazzaz, Sudad, Kedar, Sachin, Khan, A. Basit, Khan, Bilal Shahzad, Khan, Rizwan, Khare, Sarthak, Khawaja, Hussain R., Kim, Byung, Kirchner, Robert M., Kohn, Robert, Kojic, Erna Milunka, Kokkirala, Aravind Rao, Konstantino, Yuval, Kopyt, Nelson, Kosinski, Lindsay R., Kostroun, Katherine, Koulouridis, Ioannis, Kreider, Timothy R., Krishnamohan, Prashanth, Kukreja, Mohit, Kumbar, Lalathaksha, Kurss, David I., Kurz, Sebastian G., Kutschke, Michael, LaCamera, Peter, LaCasce, Ann S., Lakin, Ashley, Lakshmikanth, Jayanth, Lam, Uyen T., Lauder, Jhenette, Leach, Nykia, Leavitt, David A., Lee, Kachiu C., Lemme, Nicholas J., Leopold, Beth, Li, Jian, Li, Suqing, Lightner, Donita Dillon, Linder, Stanley, Lord, Kito, Lowenhaupt, Elizabeth A., Lee Lowery, Curtis, III, Lucier, David J., Jr., Maciag, Michelle C., Magee, Susanna R., Majczak, Marta, Majmudar, Shefali, Makai, Gretchen, Malhotra, Pieusha, Manjrekar, Eishita, Mansfield, Abigail K., Marcaccio, Stephen E., Maskin, Lauren J., Matera, Robert, Matson, Kelly L., Mazumdar, Maitreyi, Mbuyi, Nadine, McCulloh, Russell J., McDonald, Christopher, McGuirk, Barbara, Mercado, Jorge, Merrill, Scott J., Merriman, Jennifer B., Merritt, Rory, Mertz, Brittany N., Metcalfe-Klaw, Robin, Michaud, Gaetane, Minami, Taro, Minhas, Hassan M., Minkel, Jared D., Mirza, Farhan A., Mistry, Hetal D., Modest, Jacob, Monachese, Marc, Mordehai, Eveline, Morgan, Theresa A., Mughal, Aleem I., Mujib, Marjan, Mukkamalla, Shiva Kumar R., Murthy, Vivek, Nadeem, Omar, Najem, Catherine E., Naseri, Hussain Mohammad H., Nasir, Uzma, Neithardt, Adrienne B., Nguyen, Peter, Ni, Samantha, Nothnagle, Melissa, Novak, James E., Nunneley, Chloe Mander, Nuss, Emily E., O’Brien, Gail M., O’Donnell, Ryan M., Olszewski, Adam J., Orchowski, Lindsay M., Orman, Sebastian, Owens, Brett D., Pace, Paolo G., Papafilippaki, Argyro, Pappas-Taffer, Lisa, Pares, Marco, Parulkar, Anshul, Patel, Birju B., Patel, Devan D., Patel, Nima R., Patel, Pranav M., Patel, Saagar N., Patel, Shivani K., Patel, Shyam A., Patrick, Brett, Paul, Grace Rebecca, Paxton, E. Scott, Perazella, Mark, Pham, Lily, Pham, Long, Phillips, Katharine A., Pickett, Christopher, Pinkston, Justin, Plante, Wendy A., Plumley, Kevin V., Pohlen, Michael, Hartman Polensek, Sharon S., Poonsombudlert, Kittika, Posner, Donn, Prashar, Rohini, Pressman, Amanda, Prince, Adam J., Qawi, Imrana, Qureshi, Reema, Rader, Nora, Raducha, Jeremy E., Rafeq, Samaan, Rana, Neha, Ranieri, Gina, Rathore, Bharti, Rathore, Ritesh, Raukar, Neha P., Reagan, John L., Reddy, Bharathi V., Reddy, Chakravarthy, Reddy, Snigdha T., Reginato, Anthony M., Reich, Michael S., Reichart, James P., Carlin Reid, Daniel Brian, Reus, Victor I., Reyes, Candice, Rich, Harlan G., Richards, Rocco J., Riddell, Nathan, Righi, Giulia, Rivera, Alvaro M., Roberts, Nicole A., Roberts, Todd F., Rachu, Gregory, Rosenfeld, Emily, Roth, Julie L., Rougas, Steven, Roussel, Breton, Rubeor, Amity, Ruhstaller, Kelly, Safi, Javeryah, Saks, Emily, Samaniego-Picota, Milagros, Sampat, Radhika, Satpathy, Hemant K., Satpathy, Ruby K., Sayeed, Syeda M., Scaramangas-Plumley, Daphne, Schaffner, Aaron, Scheel, Paul J., Jr., Schlussel, Bradley, Schmitt, Heiko, Sciscione, Anthony, Scully, Christina D., Sell, Peter J., Sepe, Steven M., Shaban, Hesham, Shah, Ankur, Shah, Kalpit N., Shah, Shivani, Sharma, Esseim, Sharma, Yuvraj, Sharp, Lydia, Sherrod, Charles Fox, IV, Shill, Jessica E., Shlossman, Philip A., Shrestha, Asha, Shull, Jordan, Siddiqui, Khawja A., Sieczkowski, Lisa, Sigman, Mark, Simon, James, Singh, Harinder P, Singhal, Divya, Sittard, Lauren, Skylar-Scott, Irina A., Sladky, John, Slingsby, Brett, Smith, Jeanette G., Smith, Jonathan H., Smith, Matthew J., Sohur, U. Shivraj, Soi, Vivek, Soinski, Rebecca, Soler, Maria E., Soman, Sandeep, Sood, Akshay, Sperati, C. John, Steiner, Johannes, Stern, Ella, Stockwell, Philip, Sudhakar, Padmaja, Suri, Jaspreet S., Sushereba, Elizabeth, Swaminathan, Arun, Sweeney, Joseph, Syed, Wajih A., Tabba, Maher, Tammaro, Dominick, Taylor, Alan, Tellioglu, Tahir, Testa, Edward J., Thakkar, Jigisha P., Thomas, Anthony G., Thome, Andrew P., Jr., Tibbetts, Erin, Tien, Alexandra Meyer, Tien, David Robbins, Toma, Helen, Tong, Iris L., Tooley, Brett L., Treon, Steven P., Triplett, Thomas M., Trivedi, Hiresh D., Trivedi, Vrinda, Tryforos, Margaret, Tsukada, Hisashi, Tucci, Joseph R., Tuchayi, Sara Moradi, Tukey, Melissa H., Uduman, Junior, Uiterwyk, Sean H., Ullrich, Nicole J., Ungar, Leo, Uy, Bryant, Vakili, Babak, Van Kirk, Emily, Vaughan, Jennifer E., Vutescu, Emil Stefan, Wagner, Brent T., Walker, J. Richard, III, Walther, Ray, Wang, Connie, Wang, Danielle, Waroich, Jozal, Weiss, Emma H., Welesko, Mary-Beth, Werth, Adrienne, White, Matthew J., White, Paul, Whitney, Estelle H., Wicklund, Matthew P., Wincze, Jeffrey P., Wincze, John P., Wolpert, Marlene Fishman, Wu, Tzu-Ching (Teddy), Wylie, John, Yang, Nicole B., Yee, Jerry, Yesodharan, Gemini, Yip, Agustin G., Young, John Q., Young, Matthew H.H., Yusufani, Reem, Zahm, Caroline, Zeitler, Evan, Zenlea, Talia, Zimmerman, Mark, and Zouk, Aline N.

Published
2021
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24. A low complexity pre‐distortion scheme for power amplifier linearization in wideband applications

Author

Varahram, Pooria, Dooley, John, Finnerty, Keith, and Farrell, Ronan

Abstract

In this paper, a nonlinear autoregressive with exogenous inputs (NARX) digital pre‐distortion scheme to linearize power amplifiers is proposed. The proposed NARX digital pre‐distortion gives better accuracy and spectral leakage suppression compared with other commonly used Volterra‐based techniques. The stability criterion of the NARX digital pre‐distortion is derived from the frequency domain analysis. Simulation is carried out with a 20 MHz single carrier long‐term evolution signal and two‐carrier long‐term evolution signal and instantaneous to average ratio of 6.2 dB at 0.01% complementary cumulative distribution function (CCDF). The results of simulation analysis show a slight improvement in adjacent channel leakage ratio performance with 30% reduction in the number of floating point operations compared with conventional pre‐distortion techniques.

Published
2016

25. Combined FRM and GDFT filter bank designs for improved nonuniform DSA channelisation

Author

Palomo-Navarro, Ãlvaro, Farrell, Ronan, and Villing, Rudi

Abstract

Multi standard channelization for base stations is a big application of Generalised Discrete Fourier Transform Modulated Filter Banks (GDFT-FB) in digital communications. For technologies such as Software-Defined Radio (SDR) and Cognitive Radio (CR), non uniform channelizers must be used if frequency bands are shared by different standards. However, GDFT-FB based non-uniform channelizers can suffer from high filter orders when applied to wideband input signals. In this paper various combinations of GDFT-FB with the Frequency Response Masking (FRM) technique are proposed and evaluated for both uniform and non uniform channelization applications. Results show that the proposed techniques achieve savings in both the number of filter coefficients and the number of operations per input sample.

Published
2016
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26. ROUTE-TO-PA H2020 Project: Raising open and user-friendly transparency-enabling technologies for public administrations

Author

Scarano, Vittorio, Malandrino, Delfina, Baker, Michael, Détienne, Françoise, Andriessen, Jerry, Pardijs, Mirjam, Ojo, Adegboyega, Porwol, Lukasz, Szufel, Przemyslaw, Kamiński, Bogumil, Meijer, Albert, Ruijer, Erna, Forrester, John, Clementino, Giuseppe, Trochidis, Ilias, Banos, Vangelis, Andriessen, Martin, van de Klashorst, Jan Pieter, Riordan, Pauline, Farrell, Ronan, Boscolo, Paolo, Palmisano, Elena, van de Rwaal, Sander, Gray, Jonathan, Satta, Matteo, Legale, Eric, Katsikas, Sokratis K., Sideridis, Alexander B., Public Management, UU LEG Research USG Public Matters Public Governance and Management, and UU LEG Research USG Public Matters

Subjects
Social network, Open data, Taverne, Transparencyenhancing tools, Transparency, Horizon 2020 project, Computer Science(all)
Abstract

In this short paper, we introduce ROUTE-TO-PA project, funded by European Union under the Horizon 2020 program, whose aim is to improve the transparency of Public Administration, by allowing citizens to make better use of Open Data, through collaboration and personalization.

Published
2015

27. A Novel Physical Layer Authentication With PAPR Reduction Based on Channel and Hardware Frequency Responses.

Author

Ramabadran, Prasidh, Afanasyev, Pavel, Malone, David, Leeser, Miriam, McCarthy, Darragh, O'Brien, Bill, Farrell, Ronan, and Dooley, John

Subjects
WIRELESS communications, BANDWIDTHS, HARDWARE, WIRELESS channels
Abstract

Next generation wireless communications such as 5G are expected to feature wide channel bandwidths on the order of hundreds of MHz. As bandwidths increase, circuit impairments caused by frequency dependent behaviour such as ripple and tilt in gain and group delay become more significant. PAPR of OFDM signals also increase with increasing number of sub-carriers. Transmitter circuit characterisation for the wide-band frequency response is needed to pre-compensate the signal to be transmitted. In this article, we propose a novel scheme which uses the circuit characteristics combined with the channel response to generate the keys for encrypting signals to provide an additional tier of security at the physical layer. The modulated constellation of the signal of interest is encrypted by dispersing its phases in addition to encrypting the bits using Diffie Hellman scheme. It is also shown that the method is able to reduce the PAPR of OFDM signals. This scheme is experimentally validated from end-to-end on a millimetre wave wireless link at 28.9 GHz demonstrating security against a well-positioned eavesdropper and a reduction of PAPR by 3.5 dB in a 2048 point OFDM signal with 1664 active QPSK modulated sub-carriers. [ABSTRACT FROM AUTHOR]

Published
2020
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28. To avoid Hep B reactivation, screen before immunosuppression.

Author

Farrell, Ronan, Leroy, Kyley, and Nunes, Frederick

Subjects
*CHRONIC hepatitis B, *HEPATITIS associated antigen
Abstract

Universal HBV screening before immunosuppression is prudent and cost effective, even when local HBV prevalence is just 0.3%. [ABSTRACT FROM AUTHOR]

Published
2019

29. Revisiting the MIMO Capacity With Per-Antenna Power Constraint: Fixed-Point Iteration and Alternating Optimization.

Author

Pham, Thuy M., Farrell, Ronan, and Tran, Le-Nam

Abstract

In this paper, we revisit the fundamental problem of computing MIMO capacity under per-antenna power constraint (PAPC). Unlike the sum power constraint counterpart which likely admits water-filling-like solutions, MIMO capacity with PAPC has been largely studied under the framework of generic convex optimization. The two main shortcomings of these approaches are 1) their complexity scales quickly with the problem size, which is not appealing for large-scale antenna systems and/or 2) their convergence properties are sensitive to the problem data. As a starting point, we first consider a single user MIMO scenario and propose two provably-convergent iterative algorithms to find its capacity, the first method based on fixed-point iteration and the other based on alternating optimization and minimax duality. In particular, the two proposed methods can leverage the water-filling algorithm in each iteration and converge faster, compared with current methods. We then extend the proposed solutions to multiuser MIMO systems with dirty paper coding-based transmission strategies. In this regard, capacity regions of Gaussian broadcast channels with PAPC are also computed using closed-form expressions. Numerical results are provided to demonstrate the outperformance of the proposed solutions over existing approaches. [ABSTRACT FROM AUTHOR]

Published
2019
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30. TX Leakage Cancellation with Adaptive Delay Filter

Author

Su, Han, Szczepkowski, Grzegorz, and Farrell, Ronan

Subjects
Electronic Engineering
Abstract

In an Frequency-Division Duplexing (FDD) transceiver, a high power transmitted signal can leak into the RX chain due to limited isolation of a duplexer. Such signal is known as TX leakage and can seriously affect the performance of the receiver. A transmitter leakage canceller structure is proposed in this paper in order to improve isolation between the transmitter and receiver. The simulations show the proposed structure increases the isolation of a Surface Acoustic Wave (SAW) duplexer by more than 25 dB in 20 MHz bandwidth

Published
2014

31. Utilizing Sparse-Aware Volterra for Power Amplifier Behavioral Modeling

Author

Finnerty, Keith, Dooley, John, and Farrell, Ronan

Subjects
Electronic Engineering
Abstract

This paper presents a method for reducing the number of weights in a time series behavioral model for a power amplifier. The least-absolute shrinkage and selection operator (Lasso) algorithm is used to reduce the kernel size, preserving the important kernels, while eliminating the less important kernels. The algorithm is evaluated on a behavioral model for a class AB amplifier, the algorithm reduces the number of weights by greater than 70% without degrading model performance by a significant amount.

Published
2014

32. Wide Band Switched Delay Line using MEMS Switches

Author

Ibrahim, Sarah, Szczepkowski, Grzegorz, and Farrell, Ronan

Subjects
Electronic Engineering
Abstract

This paper presents a high precision wide band switched delay line with fine tuning capability and low insertion loss. The circuit is designed to operate in the frequency range from 1 GHz to 5 GHz and tuned using MEMS switches targeting a minimum delay step of 7 ps. The delay line uses a single layer of a high permittivity substrate ("r =10), and the MEMS devices are interconnected using conventional coplanar waveguide technology (CPW). The circuit was designed and simulated using CST Microwave Studio. The simulated group delay shows a small deviation from the linear phase of less than 1o over a wide bandwidth compared to the performance of SAW and ceramic filters [1]. The simulation results shows an insertion loss and a return loss of better than 1 dB and 20 dB respectively.

Published
2014

33. Characterising Spatial Relationships in Base Station Resource Usage

Author

Carolan, Emmett, McLoone, Seamus, and Farrell, Ronan

Subjects
Electronic Engineering
Abstract

This work preliminarily introduces an up to date measurement-driven examination of the spatial characteristics of network resource usage. The data set used is from a large nationwide 3G cellular network comprised of several thousand base stations. Firstly, we discuss our data set and how it can be appropriately used. Next, we examine the spatial correlation between base stations in terms of radio resource usage. We find significant spatial correlation, particularly for proximate base stations. We also examine the causality structure in the network using Granger causality and explore a metric for the identification of key indicator base stations. These indicator base stations act as hubs in the wider network and provide additional information about the future states of their neighbors. Finally, we conclude with a brief discussion of how we wish to build on this work.

Published
2014

34. A Low-Rate Identification Scheme of High Power Amplifiers

Author

Wang, Ziming, Dooley, John, Finnerty, Keith, and Farrell, Ronan

Subjects
Electronic Engineering
Abstract

A novel low-rate identication method for high power ampliers with memory-effect is presented. It is demonstrated that the required bandwidth of the feedback signal is not required to be greater than twice the signal modulation bandwidth, but is instead determined by the number of feedback samples and the degree of freedom of coefcients in the behavioral model. As the experimental measurements and extracted power amplier model show, this method can achieve a much better NMSE accuracy of modeling power amplier with nonlinear memory-effects compared with previously published approaches

Published
2014

35. A Modular Testbed for Hardware Reconfigurable Radio at the 2.4 GHz ISM Band

Author

Baldwin, Gerard, Farrell, Ronan, Baldwin, Gerard, and Farrell, Ronan

Subjects
ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, Electronic Engineering
Abstract

A modular testbed for use in developing software defined radio is documented in this paper. The testbed is focused on the 2.4 GHz ISM band but may be used at other frequencies. An RF transceiver with variable transmit/receive frequencies and bandwidths is provided. It provides the capability to support many modulation schemes and standards such as GSM, UMTS< IEEE 802.11b and parts of the IEEE802.16 standards. It performs the RF functions of the radio, with the other PHY and MAC layer functions such as equalisation and error-coding being performed by a host computer. It communicates with the host computer system through a USB2 interface allowing data rates of up-to 60Mbytes a second. An API is used for communications with the host computer system allowing for modulation/demodulation and coding/decoding in software on the host system and reconfiguration of the radio system

Published
2005

36. Modelling and Design of High-Order Phase Locked Loops

Author

Daniels, Brian, Baldwin, Gerard, Farrell, Ronan, Daniels, Brian, Baldwin, Gerard, Farrell, Ronan, and McLoone, Sean

Subjects
TheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGES, Computer Science::Logic in Computer Science, Computer Science::Computational Complexity, Electronic Engineering
Abstract

In this paper a new stable high order Digital Phase Lock Loop (DPLL) design technique is proposed. This technique uses linear theory to design the DPLL. The stability of the DPLL is guaranteed by placing a restriction on the system gain. This stability boundary is found by transforming the system transfer function to the Z-domain and plotting the root locus of the LPLL for values of gain where all the system poles lie inside the unit circle. The max value of gain where all the poles lie inside the unit circle is the stability boundary. It is shown that the stability boundary of the LPLL is comparable to the stability boundary of the DPLL. Finally where the above Bessel filter system produces slow lock, gear shifting of the DPLL components is considered. This allows the DPLL to start off with a wide loop bandwidth and switch to the narrow bandwidth once the system has locked.

Published
2005

37. Using large signal S-parameters to design low power class-B and class-C CMOS cross-coupled voltage controlled oscillators

Author

Szczepkowski, Grzegorz and Farrell, Ronan

Subjects
Electronic Engineering
Abstract

This article presents a method for design of cross-coupled LC oscillators using open-loop technique and large signal scattering matrix parameters (S-parameters) in place of well known and established negative resistance approach. Thanks to the open-loop methodology, the main circuit parameters such as loaded quality factor, steady-state oscillation amplitude and signal frequency under large signal regime can be extracted without, often tedious and time consuming, transient simulations. The most important aspect of the proposed method is its ability to provide relatively simple and intuitive representation of a cross-coupled oscillator under changing bias conditions, with 10% accuracy in comparison to analysis in time domain. The presented methodology is not technology specific, however CMOS was chosen due to its availability, relative low cost and popularity of circuit implementation. The article shows two low power, sub-1 V voltage controlled oscillator prototypes, one operating in class-B, the other one in class-C, designed using the described method and operating under the reduced power supply requirements yet retaining a state of the art Figure of Merit (FoM) of various VCO reported in the literature.

Published
2013

38. Design of a reconfigurable front‐end for a multistandard receiver for the frequency range of 800 MHz to 2.5 GHz.

Author

Zare Fatin, G., Koozehkanani, Z. D., Fotowat‐Ahmady, Ali, Sobhi, Jafar, and Farrell, Ronan

Subjects
RADIO frequency, RADIO measurements, RECONFIGURABLE robots, ADAPTIVE computing systems, WIRELESS LANs
Abstract

Summary: In this paper, a reconfigurable receiver front‐end for the frequency range of 800 MHz to 2.5 GHz is presented. The radio frequency front‐end is realized in wideband form with reconfigurable baseband filter. The proposed front‐end targets the GSM, WLAN, WCDMA, and GPS standards residing in the aimed frequency range. The necessary specifications for each individual standard have been revisited and recalculated. The interaction of the different standards and their interoperability has been thoroughly investigated and extra specifications derived for the multistandard receiver. The multistandard receiver has been designed, layouted, and simulated in RFCMOS 0.18‐μm process. [ABSTRACT FROM AUTHOR]

Published
2018
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39. Efficient Zero-Forcing Precoder Design for Weighted Sum-Rate Maximization With Per-Antenna Power Constraint.

Author

Pham, Thuy M., Farrell, Ronan, Dooley, John, Dutkiewicz, Eryk, Nguyen, Diep N., and Tran, Le-Nam

Subjects
*MIMO systems, *WIRELESS communications, *CONSTRAINED optimization, *APPROXIMATION theory, *CONVERGENCE (Telecommunication)
Abstract

This paper proposes an efficient (semi-closed-form) zero-forcing (ZF) precoder design for the weighted sum-rate maximization problem under per-antenna power constraint (PAPC). Existing approaches for this problem are based on either interior-point methods that do not favorably scale with the problem size or subgradient methods that are widely known to converge slowly. To address these shortcomings, our proposed method is derived from three elements: minimax duality, alternating optimization (AO), and successive convex approximation (SCA). Specifically, the minimax duality is invoked to transform the considered problem into an equivalent minimax problem, for which we then recruit AO and SCA to find a saddle point, which enables us to take advantages of closed-form expressions and hence achieve fast convergence rate. Moreover, the complexity of the proposed method scales linearly with the number of users, compared to cubically for the standard interior-point methods. We provide an analytical proof for the convergence of the proposed method and numerical results to demonstrate its superior performance over existing approaches. Our proposed method offers a powerful tool to characterize the achievable rate region of ZF schemes under PAPC for massive multiple-input multiple-output. [ABSTRACT FROM PUBLISHER]

Published
2018
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40. Dual wide‐band miniaturized negative group delay circuit using open circuit stubs.

Author

Taher, Hany and Farrell, Ronan

Subjects
*ENERGY bands, *BANDWIDTHS, *MICROSTRIP antennas, *ELECTRIC circuits, *ELECTRIC resistors
Abstract

Abstract: In this letter, dual band negative group delay circuit (DBNGDC) utilizing a couple of one quarter guided wave length ( λ g 4) open circuited stubs (OCSs) is presented. The centre frequencies ( f 01,2) are fully controlled with the stub lengths. On the other hand, the target negative group delay (NGD) is obtained using couple of resistors ( R 1,2) that connect each OCS to the main microstrip line. The designed DBNGDC accomplishes 52% size diminution compared with smallest size has ever been achieved before. Moreover, 0.2 and 0.4 GHz zero‐NGD bandwidths (BW) are achieved. [ABSTRACT FROM AUTHOR]

Published
2018
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41. A low complexity peak-to-average power ratio reduction scheme based on selected mapping and radix-II IFFT in OFDM systems.

Author

Kazemian, Mohsen, Varahram, Pooria, Hashim, S. J., Ali, Borhanuddin M., and Farrell, Ronan

Subjects
FOURIER transforms, COMPUTATIONAL complexity, ELECTRONIC data processing, SPECTRAL energy distribution, FREQUENCY division multiple access
Abstract

Because of its lack of feedback process and the simplicity of its searching algorithm, conventional selected mapping (CSLM) is an efficient peak-to-average power ratio (PAPR) reduction technique in orthogonal frequency division multiplexing systems compared to the present techniques such as partial transmit sequence and active constellation extension. The requirement for large numbers of inverse fast Fourier transform (IFFT) blocks to provide desired PAPR reduction performance is introduced as the most significant drawback of the CSLM. This paper uses the special structure of an N-point radix-II IFFT in the CSLM and proposes a low complexity method to reduce the redundant calculations with almost the same PAPR reduction, bit-error rate, and power spectral density performances as those of the CSLM. The simulation results show that the computational complexity is reduced by at least 46.8% compared to that of the CSLM with approximately the same PAPR performance. [ABSTRACT FROM AUTHOR]

Published
2018
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42. Undersampling Observation-Based Compact Digital Predistortion for Single-Chain Multiband and Wideband Direct-to-RF Transmitter.

Author

Wang, Ziming, Farrell, Ronan, and Guan, Lei

Subjects
*RADIO transmitter-receivers, *BROADBAND communication systems, *ANALOG-to-digital converters, *POWER amplifiers, *ELECTRIC circuits, *CHARTS, diagrams, etc.
Abstract

Modern wireless network operators are consistently looking for improvements in the wireless access infrastructure that minimize size, weight, and power. Therefore, compact multiband RF and wideband RF solutions offer an attractive role in forthcoming fifth generation networks. This paper presents a novel compact wideband RF transmitter architecture that is based upon an undersampled digital predistortion (DPD) methodology. The proposed architecture minimizes the required number of RF/analog components in the system by using RF-DAC-based direct RF sampling at the forward transmitter data path and one undersampled analog-to-digital conversion (ADC) with certain bandpass filters at the DPD sampling receiver path. Extensive experimental results validate that the DPD-enabled RF transmitter bandwidth can be significantly increased using the proposed multirate track-and-hold amplifiers architecture. Experimental tests achieved multiple GHz DPD bandwidths with satisfactory linearization performance via very compact sampling receiver that has one undersampled ADC. Particularly, we evaluated three application scenarios: 1) three-band carrier aggregated LTE signals (each one occupying 20-MHz instantaneous bandwidth), the linearization performance achieved 50-dBc adjacent channel power ratio (ACPR) with more than 1-GHz bandwidth using ADC running at 76.8 and 61.44 MSPS; 2) single-band LTE signal with continuous 100-MHz instantaneous bandwidth, the linearization performance achieved −48-dBc ACPR using 61.44-MSPS ADC; and 3) single-band LTE signal with continuous 20-MHz bandwidth at 4 GHz, the linearization performance achieved −54-dBc ACPR using 61.44-MSPS ADC. [ABSTRACT FROM PUBLISHER]

Published
2017
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43. Towards a Quantitative Model of Mobile Phone Usage Ireland – a Preliminary Study

Author

Farrell, Ronan, Carolan, Emmett, McLoone, Seamus C., and McLoone, Sean F.

Subjects
Electronic Engineering
Abstract

Mobile phone networks were traditionally voice and SMS messaging networks which made them easy to quantify and model. More recently with the advent of broadband data connections and smart phones, mobile phone networks are being used for a wide range of purposes using ever more bandwidth. This paper utilises data provided by an Irish operator to provide an initial perspective on the current uses of mobile phone networks as a within Ireland. This work serves as a precursor to the development of a quantitative model of existing behaviour which in turn will help predict future requirements.

Published
2012

44. 10 GHz, Class-B, 0.5 V, 130 nm CMOS Cross-Coupled Oscillator Design Using Open-Loop Technique

Author

Szczepkowski, Grzegorz and Farrell, Ronan

Subjects
Institute of Microelectronic & Wireless Systems, Hardware_INTEGRATEDCIRCUITS, Hardware_PERFORMANCEANDRELIABILITY, Electronic Engineering
Abstract

The paper presents a method for design of LC cross-coupled oscillators based on open-loop technique and its practical application leading to a high frequency CMOS oscillator prototype. Thanks to the proposed approach, main circuit parameters as loaded quality factor (responsible for phase noise performance of LC oscillator) and steady-state oscillation amplitude can be extracted, without the necessity of time consuming transient simulations. The presented method is not technology specific and allows fast calculations under changing bias conditions. The proposed 130 nm CMOS prototype operates 10 GHz from 0.5 V power supply achieving SSB phase noise of -113 dBc/Hz at 1 MHz offset from the carrier. Low power consumption of 1.09 mW RMS, has been obtained by biasing the oscillator devices to operate in class-B i.e. VGS =Vth.

Published
2012

45. Analysing Ireland’s Interurban Communication Network using Call Data Records

Author

Carolan, Emmett, McLoone, Seamus C., McLoone, Sean F., and Farrell, Ronan

Subjects
Electronic Engineering
Abstract

This work utilises data from an Irish mobile phone network to provide a preliminary, but novel, analysis of the interurban communication network between twenty five of the largest cities and towns in Ireland. An intuitive technique is applied to a mobile phone operator’s call detail records to identify the actual subscriber population of different urban areas with various penetration rates. Weighted communication links are generated between the urban centres based on spatial and temporal metrics of distance, and are examined for different times of the day and for different days of the week. These communication links are compared to the output of a standard gravity model in order to ascertain the latter’s ability to accurately represent Ireland’s interurban communication network. The results obtained are presented and discussed within.

Published
2012

46. Material culture in rural Ireland

Author

Farrell, Ronan, Bucholz, Merritt, Carroll, Peter, and Ryan, Anna

Subjects
architecture, theatre, Mayo
Abstract

non-peer-reviewed The objective of this thesis is to explore theatrical space and the cultural relationship of materials as they are experienced by people in rural Ireland. The method involved the investigation of five handball alleys in Co.Mayo, the identification of materials and the location of the sources of those materials. The results found that one of these handball alleys was part of an urban arrangement of theatrical spaces. The alley was no longer in use, in a state of disrepair and the materiality experience was lost due to the ivy covering the walls. I propose for this project a reuse of the site as a theatre with poetry with an associated playwright hostel, using this to explore a nomenological approach to design through the relationship of old and new materials with reference to past and present culture. TOC: Introduction / Primer projects in Shannon and Hamburg / Chapter One - Theatrical Space / -Theatre in everyday life / -Three Theatre Experiences / Chapter Two - Material / -Physicality of materials / -Sense of Place / Chapter Three - Investigation / -Learning From Alleys / -Advanced Construction / Conclusion - Final Presentation / Bibliography

Published
2011

47. A 90nm, Low Power VCO with Reduced KVCO and Sub−band Spacing Variation

Author

Collins, Diarmuid, Keady, Aidan, Szczepkowski, Grzegorz, and Farrell, Ronan

Subjects
Electronic Engineering
Abstract

In this paper we present the design of a low power VCO with reduced variations in VCO gain (KVCO) and subband spacing resolution (fres). The proposed VCO is designed using a 90nm CMOS process to cover a tuning range of 23%. Variations in KVCO and fres are reduced by factors of 6 and 17 respectively over a conventional sub-banded VCO, designed using the same process, to meet the same tuning range. This makes the proposed VCO more suited to stable PLL operation with its reduced KVCO requirements resulting in an improvement in phase noise performance over the conventional VCO by 2 dB. Due to the reduced loading on the VCO tank achieved by the presented design, power consumption is kept extremely low at 850 μW from a 1 V supply

Published
2011

48. Fast Digital Calibration of Static Phase Offset in Charge-Pump Phase-Locked Loops

Author

Collins, Diarmuid, Keady, Aidan, Szczepkowski, Grzegorz, and Farrell, Ronan

Subjects
Hardware_INTEGRATEDCIRCUITS, Electronic Engineering
Abstract

Mismatches within the charge pump (CP) deteriorate the spectral perfor- mance of the CP-PLL output signal resulting in a static phase offset. Classical analog approaches to reducing this offset consume large silicon area and increase gate leak- age mismatch. For ultra-deep-submicron (UDSM) technologies where gate leakage in- creases dramatically, reduction of static phase offset through digital calibration becomes more favorable. This paper presents a novel technique which digitally calibrates static phase offset down to < 10 ps for a PLL operating at 4.8 GHz, designed using a 1V 90nm CMOS process. Calibration is completed in only 2 steps, making the proposed technique suitable for systems requiring frequent switching such as frequency hopping systems commonly used in today’s wireless communication systems.

Published
2011

49. Analysing Ireland's Social and Transport Networks using Sparse Cellular Network Data

Author

Kelly, Daniel, Doyle, John, and Farrell, Ronan

Subjects
Electronic Engineering
Abstract

This work utilises data from a mobile phone network to observe the com- munication and movement patterns of the Irish population between specic locations. A novel technique is applied to mobile phone network billing data to estimate the distri- bution of the phone network population across the country at key times, namely home times and work times. From these population distributions, sets of weighted trans- portation and communications links between locations are generated. These networks are analysed using indicators commonly employed in network theory such as cluster- ing coecients and betweenness centrality. Furthermore, the ability to generate such weighted links when phone network data is unavailable is investigated.

Published
2011

50. Design Technique of Broadband CMOS LNA for DC-11GHz SDR

Author

Tuan-Phan, Anh and Farrell, Ronan

Subjects
Electronic Engineering
Abstract

This paper presents a DC-11GHz CMOS low noise amplifier (LNA) for software-defined radio (SDR). The broadband performance is extended to cover the spectrum from near DC to 11GHz by adopting extra inductors with modified resistive feedback, folded current reuse topology. Bandwidth extension is proposed by inserting pole splitting, interstage and LC ladder inductors. A source follower jointly acts as the buffer stage for broadband output matching and feed-forward path for gain enhancement as well as noise cancellation. Simulation shows power gain of 11 ±4dB and the NF ranging from 1.8 to 3dB in 0.4-11GHz band. The LNA achieves an average IIP3 of -10dBm while consumes only 5.3mW. The proposed broadband LNA is designed in 0.18-µm CMOS process from 1.5V supply.

Published
2010

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