14 results on '"ERROR probability"'
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2. Ekolojik Ahşap Yapı Restorasyonunda Kullanılan Aşındırma İşlemi ve Basınç Direnci Üzerine Etkisinin İncelenmesi.
- Author
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Kemal BAYRAKTAR, D. and İsmail KESİK, H.
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ERROR probability ,RESTORATION ecology ,SODIUM bicarbonate ,FACTOR structure ,SPRUCE - Abstract
Copyright of Düzce University Journal of Forestry / Düzce Üniversitesi Orman Fakültesi Ormancılık Dergisi is the property of Duzce University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
3. İKİ ORTALAMANIN KARŞILAŞTIRILMASINDA ÖRNEK BÜYÜKLÜĞÜNÜN TAHMİNİ VE BAZI İSTATİSTİK PROGRAMLARIN KULLANIMI.
- Author
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TOPAL, Mehmet and ÖZ, Recep
- Abstract
In this study, we focused on what the least sample size is at I and II type error level in comparisons of paired and independent group averages and used PS and PASS programmes to estimate sample size. Similar results were obtained from both programmes. In the comparison of the averages of paired and independent groups, we took 0,05, 0,025, 0,01 and 0,001 as I type error (α), 0,10 and 0,20 as II type (β). As error level decreases, so does the size of sample increases. In addition, the difference between population averages and the extent of standard deviation value belonging to sample values have an important effect on sample size. [ABSTRACT FROM AUTHOR]
- Published
- 2022
4. Error Probability Analysis of a Composite Weibull/Log-Normal Fading Channel
- Author
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Mehmet BİLİM
- Subjects
Weibull/log-normal ,error probability ,cumulative distribution function. ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Science ,Science (General) ,Q1-390 - Abstract
In this study, error probability of a single-input single-output (SISO) system is investigated over a composite Weibull/log-normal fading channel. We aim to study a SISO system in the composite Weibull/log-normal composite fading model which is useful in characterizing fading effects in numerous realistic communication scenarios. Therefore, a closed-form error probability expression was derived by using cumulative distribution function (CDF) of a Weibull/log-normal fading channel. The proposed error probability expression is based on CDF and is valid for different binary digital modulation types. Results that are given in this study were confirmed by computer simulations.
- Published
- 2019
- Full Text
- View/download PDF
5. Sosyal Yargı Kuramı Perspektifinde Genç Tüketicilerin Davranışsal Niyetlerinin Oluşumunda İlgilenim Düzeylerinin Etkisi.
- Author
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ŞENBABAOĞLU DANACI, Emine and PARILTI, Nurettin
- Subjects
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THEORY of reasoned action , *TECHNOLOGY Acceptance Model , *ERROR probability , *YOUNG consumers , *MODEL theory - Abstract
The purpose of this study demonstrate the effect of involvement on the intention, which is the pioneer of buying behavior, by acting on the attitude-intention-behavior model based on Theory of Reasoned Action (TRA) and Technology Acceptance Model (TAM). This study is based on the Social Judgment Theory. Involvement was addressed in five dimensions, interest, symbolic value, hedonic value, perceived risk and probability of error. In this study, the effects of individual dimensions of the scale of involvement on behavioral intention are measured. The research model constructed using AMOS and SPSS package programs was analyzed. The main finding of this study is that the level of interest of young consumers influences behavioral intentions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
6. Sayısal modülasyonların η-μ/gamma karma sönümlenmeli ortamlardaki hata olasılığı üzerine bir çalışma.
- Author
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BİLİM, Mehmet
- Subjects
- *
FREQUENCY shift keying , *DIFFERENTIAL phase shift keying , *PHASE shift keying , *DIGITAL modulation , *RAYLEIGH fading channels , *ERROR probability , *DIGITAL communications , *PROBABILITY density function - Abstract
In this study, performance analysis of η-μ/Gamma mixed fading channels of communication systems using noncoherent frequency shift keying and differential phase shift keying digital modulation types is presented. The analysis is based on probability density function and contains mathematically basic functions. For this reason, the proposed analysis is quite simple and understandable from a mathematical point of view. As a result of the analyzes, the closed form average error probability expression is derived. The numerical results obtained by using the derived error expression are compared with the simulation results and the accuracy of the derived expression is shown. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
7. Çöz-aktar röle-yardımlı-NOMA sistemlerinin hata başarımlarının analizi ve kullanıcılar arası adillik için bir güç paylaşım protokolü.
- Author
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Kara, Ferdi and Kaya, Hakan
- Subjects
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MONTE Carlo method , *ERROR probability , *RADIO networks , *RADIO technology , *FAIRNESS , *PROBABILITY theory , *COGNITIVE radio , *RADIO transmitter fading - Abstract
Non-orthogonal multiple access (NOMA) is a major candidate technology for the future radio networks due to its potential to have high spectral efficiency and to support massive connections. It is also an important advantage for the NOMA to be very compatible with the other physical layer techniques. The relay-aided-NOMA which consists of the interplay between cooperative communication and NOMA, offers very large coverage area besides the high spectral efficiency and the massive connectivity. Hence, the relay-aided-NOMA has great recent attention. Most of these studies are devoted to reveal outage probability and the overall system capacity performances of the systems. However, the bit error performances have been ignored. In this paper, theoretical end-to-end (E2E) average bit error probability (ABEP) expressions are derived for the relay-aided-NOMA using a relay with the decode-forward (DF) protocol. The derived expressions are validated through Monte Carlo simulations. The E2E error performance of the system are examined for different system parameters. Moreover, by considering user fairness in terms of error performance, it is discussed how the optimum power allocation should be done. And finally, a sub-optimum power allocation algorithm is presented according to the proportional fairness index. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
8. İşbirlikli-Dikgen Olmayan Çoklu Erişimin Nakagami-m Sönümlemeli Kanallardaki Hata Analizi.
- Author
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Kara, Ferdi and Kaya, Hakan
- Subjects
MONTE Carlo method ,ERROR probability ,ERROR analysis in mathematics ,RAYLEIGH fading channels ,WIRELESS cooperative communication ,SIGNS & symbols - Abstract
Copyright of Karaelmas Science & Engineering Journal / Karaelmas Fen ve Mühendislik Dergisi is the property of Karaelmas Science & Engineering Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
9. Yükseköğretime Geçiş Sınavı'nda şifreleme İddiaları ve Adayların şifrelemeyi Kullanıp Kullanmadığını Belirleyen Bir Yöntem Önerisi.
- Author
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DOğAN, M. Kadir
- Subjects
COLLEGE entrance examinations ,UNIVERSITY & college admission ,TRACK system (Education) ,HIGHER education ,ERROR probability - Abstract
Copyright of Education & Science / Egitim ve Bilim is the property of Turkish Education Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2012
10. Türkiye'de sağlık sektöründe meydana gelebilecek hata ve hilelerin önlenmesine yönelik kontroller ve bir uygulama
- Author
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Erdoğan, Burhan, Tarhan Mengi, Banu, İşletme Anabilim Dalı, Mengi, Banu Tarhan, and İşletme Anabilim Dalı Muhasebe Denetimi Bilim Dalı
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Internal control and internal audit ,Denetim ,Accounting mistakes and frauds ,Fraud ,Preventive intervention ,Sağlık Kurumları Yönetimi ,Health Care Management ,Error control ,Error ,Türkiye ,Health sector ,İşletme ,Muhasebe ,Control ,Sağlık işletmeleri ,Error probability ,Business Administration - Abstract
Tüm dünyada ekonomilerin büyümesi, ticarette sınırların kalkması, organizasyonların karmaşık hale gelmesi ve kontrolün zorlaşmasıyla birlikte hataların meydana gelmesi olasılığı artmış, hileli finansal raporlama ise büyük bir sorun haline gelmiştir. Hem işletmeler hem de kamu kurumları bu sorunu aşmak için birtakım önlemler almayı gerekli görmüşlerdir. Denetçiler bu konuda hile riskini ölçmeli, kontroller önererek işletme yönetimlerine bilgi vermelidirler. İşletmelerde baskı, fırsat ve haklı gösterme unsurlarının bir araya gelmesiyle hileler meydana gelmektedir. Hata ve hileler işletmeleri gerek finansal anlamda gerekse itibar anlamında etkilemekte ve işletmenin sürdürülebilirliği açısından riskli bir durum ortaya çıkmaktadır.Sağlık işletmelerinde iç kontrol politika ve prosedürlerinin uygulanması, prosedürlerin sürekli güncellenmesi ve çalışanlara bildirilmesi, ihbar hatlarının kurulması, dürüst çalışanların işe alınması, çalışanlara hile konulu eğitimler verilmesi, işletme etik kurallarının geliştirilmesi, işletmede hile riskinin sürekli gözlenmesi, değerlendirilmesi gibi yöntemlerle ortaya çıkan hata ve hile risklerinin en aza indirilmesi amaçlanmıştır. Bu çalışmada hastane işletmelerinde hata ve hile riskinin ölçülüp değerlendirilmesine ve ortadan kaldırılmasında uygulanan kontrollere yönelik bir araştırma yapılmıştır. Fraudulent financial reporting has become a major problem all over the world as economies grow, trade remains borders, organizations become complicated and it becomes harder to control. Both businesses and public institutions have found it necessary to take some measures to overcome this problem. Auditors should measure the risk of fraud in this regard, take preventive measures and report on their management and information. Error and fraud concepts emerge in businesses where the elements of fear, oppression, opportunity and justification exist. In the case of mistakes and mistakes, there is a risk situation in the financial sense and also in terms of reputation.Implementation of internal control policies and procedures in health enterprises, continuous updating of procedures and notification to employees, establishment of notice lines, recruitment of honest employees, training of employees on fraud, development of business ethics rules, continuous monitoring of the fraud in the business, It is aimed to reduce the most. In this study, a study was carried out to measure and evaluate the risk of error and fraud in the hospital enterprises and to check the controls applied to the removal. 120
- Published
- 2017
11. Parazit çok girişli çok çıkışlı (ÇGÇÇ) sistemlerin başarım analizi
- Author
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Haliloğlu, Ömer, Şafak, Mehmet, and Elektrik-Elektronik Mühendisliği Anabilim Dalı
- Subjects
Diversity ,Elektrik ve Elektronik Mühendisliği ,Error probability ,Antenna arrays ,Electrical and Electronics Engineering - Abstract
Telsiz iletişimde alıcıda ve vericide birden çok antenin kullanıldığı çok girişli çok çıkışlı (MIMO) sistemler kullanılarak yüksek veri hızlarına ulaşılmıştır. Ancak daha az yer kaplayan, daha az maliyetli ve daha çok veri hızı sağlayan sistemlere gereksinim duyulmaktadır.Alıcı ve verici anten sistemlerindeki antenlerden sadece birinin veya birkaçının aktif olarak beslenmesiyle ve parazit antenlerin kullanımıyla RF besleyici devreleri basitleştirilebilir. Ayrıca, antenlerin birbirlerine yakınlaşmasından dolayı anten sistemlerini daha küçük alanlara sığdırmak mümkündür. Bunun yanısıra verici çıkış gücü, antenlerden sadece birini beslemek için kullanıldığından, geleneksel MIMO sistemlerine göre daha verimli kullanılmıştır ve dolayısıyla sistemin başarımını artırmak mümkündür.Bunun için Rayleigh sönümlemeli bir kanalda, 3x3 ve 5x5 MIMO sistem modellerinde verici antenlerden birinin beslenip diğerlerinin parazit olarak kullanılması durumundaki bit hata olasılığı (BHO) ve dizi kazancı başarımları incelenmiştir. Verici antenler arasındaki ilinti, antenler arası ortak empedanslar cinsinden ifade edilmiştir. Alıcı antenler tarafından alınan sinyaller büyül oran birleştirme (BOB) kullanılarak birleştirilmiştir. Parazit antenlere bağlanan reaktif empedansların ve antenler arası uzaklığın sistem başarımına etkileri incelenmiş ve elde edilen sonuçlar geleneksel MIMO sistemlerinin başarımları ile karşılaştırılmıştır. In wireless communications, high data rates have been achieved by using multiple input multiple output (MIMO) systems. However, MIMO systems are desired to occupy less space and be less expensive. This thesis is concerned with parasitic MIMO systems, where only one or some of the antennas in the transmitter is fed actively. RF feeding circuits thus become more simple, and since antennas get closer to each other, it will be possible to fit antenna systems into smaller spaces. Besides, since only the active antenna(s) in the transmitter is fed, transmit power is used more effectively, system performance can be improved with respect to the traditional MIMO systems.Thus, bit error probability (BER) and array gain are analysed in a Rayleigh fading channel, of 3x3 and 5x5 multiple input multiple output (MIMO) systems in which only one of the transmitter antennas is fed, whereas the others are used as parasitic elements. The correlation between the transmit antennas is accounted for in terms of the mutual empedances between the antennas. The signals received by the receive antennas are combined using maximal ratio combining (MRC). Effects of reactive load empedances connected to the parasitic antennas and of the distance between antennas are analysed in comparison with the traditional MIMO systems. 70
- Published
- 2012
12. Dikgen frekans bölüşümlü çoğullama sisteminin başararım analizi
- Author
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Karabacak, Özgür, Şafak, Mehmet, and Diğer
- Subjects
Orthogonal frequency division multiplexing ,Elektrik ve Elektronik Mühendisliği ,Performance analysis ,Error probability ,Electrical and Electronics Engineering - Abstract
DİKGEN FREKANS BÖLÜŞÜMLÜ ÇOĞULLAMA SİSTEMİNİN BAŞARIM ANALİZİ Özgür KARABACAK Hacettepe Üniversitesi, Elektrik-Elektronik Mühendisliği Bölümü ÖZ Bu çalışmada dikgen frekans bölüşümlü çoğullama (OFDM) sisteminin düz ve hızlı sönümlemen kanallarda sembol-hata-oranının (SER) başarım analizi yapılmıştır. Kanal, ilintisiz (uncorrelated) izotrop olarak saçılmış ve geniş-anlamda-değişmez (WSS) olarak varsayılmıştır. Kanalın zamana bağlı olarak değişmesi ve taşıyıcı frekansındaki kayma nedeniyle, OFDM sisteminin alt taşıyıcıları arasında karışım (ICI) meydana gelir. OFDM sisteminin ICI'dan dolayı oluşan sinyal-karışım-oranı (SIR), OFDM sisteminin pratikte bir uygulaması olan HIPERLAN/2 sistemi için hesaplanmıştır. Zaman seçici sönümlemenin ve taşıyıcı frekansındaki kaymanın, HIPERLAN/2 sisteminin SER başarımı üzerindeki etkisi araştırılmış ve bu başarım zamanla hızlı değişen, ayırıcı (dispersive) ve Nakagami sönümlemeye maruz kalmış kanallar için incelenmiştir. Bu araştırmalar, OFDM sisteminin zaman seçici sönümlemeye ve taşıyıcı frekansındaki kaymalara karşı son derece hassas olduğunu göstermiştir. Bunun yanısıra, zamanla hızlı değişen, Nakagami sönümlenmiş kanallar için HIPERLAN/2 sisteminin başarım analizi L-yollu çeşitleme (L-branch diversity) için de yapılmıştır. Bu analiz en büyük oranlı birleştirme (MRC), seçici birleştirme (SC) ve eşit oranlı birleştirme (EGC) için yapılmış ve herbir birleştirme tekniğinin zamanla hızlı değişen kanallar için SER'leri hesaplanmıştır. Bulunan sonuçlar, çeşitlemeye ait yolların bağımsız- özdeş dağıldığı ve bağımsız-ayrık dağıldığı durumların her ikisi için de yapılmıştır. Ayrıca, kiplenim tekniği olarak, sönümlemen kanatlardaki sağlamlığından dolayı DPSK seçilmiş ve bu kiplenim tekniğinin başarım analizi sonucunda elde edilen nitel ve nicel sonuçlar, HIPERLAN/2 için tavsiye edilen kiplenim teknikleri (BPSK, QAM) ile karşılaştırmıştır. Anahtar Kelimeler: Dikgen frekans bölüşümlü çoğullama, HIPERLAN/2, Nakagami sönümlenme, sembol hata oranı, çeşitleme. Danışman: Prof. Dr. Mehmet ŞAFAK, Hacettepe Üniversitesi, Elektrik-Elektronik Mühendisliği Bölümü. PERFORMANCE ANALYSIS OF ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM Özgür KARABACAK Hacettepe University, Department of Electrical and Electronics Engineering ABSTRACT In this study, symbol error rate (SER) performance of orthogonal frequency division multiplexing (OFDM) is studied in frequency-nonselective, fast fading channels. The channel is assumed to be wide-sense stationary (WSS) under uncorrected isotropic scattering. Because of the time-varying characteristics of the channel and the carrier offset, inter-carrier-interference (ICI) is introduced. Exact definition of signal-to-interference ratio (SIR) of an OFDM system due to ICI is evaluated for the HIPERLAN/2 system, which constitutes a practical realization of an OFDM system. Effects of time-selective fading and frequency offset are investigated on the SER performance, and its performance over dispersive, time- varying channel is quantified for Nakagami fading. From the results, it was observed that the OFDM is very sensitive to time-selective fading and the carrier offset. The performance of an OFDM system is also analyzed for time-selective Nakagami fading with L-branch diversity reception. Maximum ratio combining (MRC), selection combining (SC) and equal gain combining (EGC) are considered. For each combining technique, closed-form expressions for the SER are derived for time-setective Nakagami fading channels. The results are presented for both independent and identically distributed (i.i.d.), and independent and nonidentically distributed diversity branches. Additionally, the performance of DPSK is analyzed, because of its robustness in fading channels, and its performance is compared to the suggested modulation techniques of HIPERLAN/2 namely BPSK and QAM. Keywords: Orthogonal frequency division multiplexing, HIPERLAN/2, Nakagami fading, symbol error rate, diversity. Advisor. Prof. Dr. Mehmet ŞAFAK, Hacettepe University, Department of Electrical and Electronics Engineering 11 114
- Published
- 2002
13. Nakagami sönümlemeli kanallarda kafes kodlamalı kiplenimin başarımının incelenmesi
- Author
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Ercek, Gamze, Şafak, Mehmet, and Diğer
- Subjects
Elektrik ve Elektronik Mühendisliği ,Modulation methods ,Nakagami distribution ,Error probability ,Trellis coding ,Electrical and Electronics Engineering - Abstract
IV ÖZET Bu çalışmada, kafes kodlamalı kiplenimin (trellis-coded modulation, TCM), toplanır beyaz Gauss gürültülü (additive white Gaussian noise, AWGN), kanalın yamsıra Rayleigh, Rice ve Nakagami dağılımlı sönümlemeli kanallardaki, başanmı incelenmiştir. Kafes kodlamalı kiplenimin genel kavramı ve temel ilkeleri özetlenmiştir. Ayrıca kullanılan kümelere ayırma (set partitioning) yöntemi anlatılmıştır. TCM' in Nakagami dağılımlı sönümlemeli kanaldaki başanmı farklı sönümleme parametre değerleri için incelenmiştir. Çalışmalar sırasında kanalın ideal bit dağıtım özelliğine sahip olduğu vede evre uyumlu olduğu varsayılmıştır. Nakagami sönümleme parametresinin artan değerlerinde başarımın arttığı sonucuna ulaşılmıştır. Son olarak çoklu TCM' in Nakagami tipi sönümlemeli kanaldaki başanmı incelenmiş ve klasik TCM ile karşılaştırmalar yapılmıştır. Analiz sonuçlan çoklu TCM' in klasik TCM' e göre daha başanlı olduğunu göstermiştir. Anahtar kelimeler: Kafes kodlamalı kiplenim, Nakagami dağılımlı sönümleme, hata olasılığı, çoklu kafes kodlamalı kiplenim. ABSTRACT In this study, trellis-coded modulation, which is a bandwidth-efficient coded modulation scheme is analyzed in various types of channels, namely, additive white Gaussian noise channel (AWGN), Rayleigh, Rician and Nakagami fading channels. The concept and fundamentals of trellis coded modulation (TCM) and the set partitioning technique as a tool for designing TCM schemes are studied. Performance of TCM over Rician and Nakagami fading channels are comparitively studied. It is observed that the increase in the Nakagami fading parameter improves the performance of TCM over Nakagami fading channel. Bit error probabilities of conventional and multiple TCM in Nakagami fading channel are derived. Multiple TCM systems are analyzed. The results show that multiple TCM has superior bit error rate performance over conventional TCM systems. Keywords: Trellis coded modulation, Nakagami fading, error probability, multiple trellis coded modulation. 109
- Published
- 2000
14. Asimetrik doğrusal olmayan sürekli fazlı frekans kaydırmalı anahtarlama
- Author
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İhtiyar, Ahmet, Aygölü, Hasan Ümit, and Diğer
- Subjects
Elektrik ve Elektronik Mühendisliği ,Switching ,Parameters ,Error probability ,Electrical and Electronics Engineering - Abstract
ÖZET Sayısal iletimde en önemli parametrelerden birisi hata olasılığıdır. Bu parametrenin iyileştirilmesi için her modülasyon tekniğinde bir takım çalışmalar yapılmaktadır. Bu tezde sürekli fazlı frekans kaydırmalı anahtarlamada çeşitli parametreler değiştirilerek daha iyi hata olasılıkları elde edilmiş ve elde edilen sonuçlar incelenerek bu sonuçların kullanılabilirliği için yorumlar yapılmıştır. IV SUMMARY în the digital- transmission, on© of the most important parameters is error performance. Some improvements are being done to make better this for all modulation techniques. Sometimes, different parameters are chanced and sometimes new modulation tehniques are developed. All these are done for getting better results on error performance. One of the developed modulation tehniques is Continuous Phase Modulation CCPMD.This is a succesful study because of its bandwidth and error probability. Narrower bandwidth, lower spektral sidelobes and better error performance can be obtained. Different types of modulations were obtained by improving CPM. These have continious phase modulation structure generaly. Difference is pulse shape of each one. Because of this, they have different names to ditinguish them. A parameter which is used in all CPMs is modulation index h. Changes on h does not chance the name of modulation but there may occour some good or bad changes. în some cases, h is fixed but in some improved modulations h is variable. This parameter chances in a period of time and gets limited different values. Error performance in this code is better then fixed h. Better performance can be get by using two or more h.In the demodulation of CPM signals, the most important parameter to determine error probability is minimum Euclidian distance. This can be get by calculating distances between all the couples of ways at the end of the each step. Minimum of these values found is Minimum Euclidian Distance dmin. Varius algorithms are used to compute distances true and quickly. For an effective dmin to find error probability, the noise must be white gausian noise and for various L and h values, different algorithms are used to find this h value. Modulator of CPM consist of a filter and a frequency modulator. Fil ter charasteristic chances according to pulse shape gCO.Vi terbi algorithm can be used in the receiver or the system. In theory, there is no problem to form receiver but in practice, there are some problems. For example, complexity in vi terbi detechtors increases with ihe memory. Minimum Shifting Keying CMSKD, a special type of Continiosu Phase Frequency Shifting Keying CCPFSO, uses parallel, type receiver. But this is not the optimum way. If we examine the structure of CPM it is seen that, phase of it, takes specific values with a p>eriod. These values are sample points of Euclidian space. Changes of phase on time is bounded with data bits. At the same time, because of the CPM schemes, phase is continious. Phase states can be sown with modulo 2jt. So that, it can be drawn on a cylinder. This type coded signals have a trellis structure and decoding can be done by vi terbi algorthm. For example, distance between codewords in binary coding is measured with Hamming distance. After that, this VIdistance is compared with nearer two neighbor codewords and the nearest one is decided. Soft decision mechanism is used. Nonlinear CPFSK is a kind of continious phase modulation. If L=.l, a kind of CPM, Spectral Raised cosine CLRECD gets a name CPFSK. A difference from the others CPMs is nonlinear t y of it. This is because, trellis of modulation is defined by a matrix. Another characteristic is that, h chances according to incoming data and phase at the begining of the time interval, h is also a function of CL-1D previous data. As a result of this, phase state at the end of any interval may be different from the phase state at the begining Minimum euclidian Distance and signal to noise ratio are effective on computing error probability of CPMs. Signal to noise ratio is fixed for a channel. So that, if the error performance will improve, dmin is effective factor. If constraint length Cm is increased, dmin will get a better value. Constraint length is the minimum step of all joining ways. During the collection of dmin, there is an integration but this calculation can be reduced to a sinus formül a. Accumul ati vity of d distance facilities calculations.lt is controlled if phase difference between start and end of interval changes. According to this, one of two formules is used. After that, all distances found for each interval are added total. CPFSK uses a matrix different from classic CPM do not use. This matrix is state transmission matrixlt shows which state will be the next state according to state at the begining and incoming data. h values can be compated by using this matrix and phase states. this modulation is a multi h modulation. So that, there are more than one hvalues. This kind of signaling technique is a multi-h phase coding technique. Matrix is same for all the signaling intervals. So the multi-H values are same for all intervals for the same data and phase conditions. This modulation can be improved by chancing some parameters. One of these parameters is phase group. Normally, phase states have the same distance with eac hot hers. Some new results can be obtained by chancing these distances. By this method, Euclidian distance reduced for some intervals and increased for the other intervals. At the end of Cm interval, totaly, dmin is increased according to equal distances. Because of assymmetry of phase states, this kind of modulation is called assymmetric nonlinear continuous phase FSK. Spectral characteristics are similar to MSK because of controlling h value. Some conditions must be paid attention during this kind of adjustment. One of these is the logic of founded results, chenges which are made must not produce alogical results. For example, founded new phases must be between O and 2tt and h values must be convinient too. After all the conditions are kept, a dmin value is found for new phase group. Wrlten algorithms are used to find this. Different algorithms are used to calculate values and show these on devices. Results founded are shown on graphics. Good or bad changes can be seen clearly from these graphics. These graphics can also be used to comment results. When drawn graphics are examined» it can be seen that, linear variation phases causes linear variation of dmin values. After this result, the important is to find optimum solution with dmin and h values. VTIIBetter error performances can be succeed in by some other ways besides examined in this study. For example, better dmin values cen be obtained by changing T period. This is a study independently and results of it must be examined careful y. Similarly, used data bits can be changed. Instead of binary, quoternary or eighternary signaling systems can be used. This is a kind of coded modulation. Frequency spectrum and new dmin values must be examined for this condition. This new technique obtained by changing phase states is not a new modulation technique. This is just an improvement on nonlinear continious phase FSK for a better error performance. Obtained results are satisfactory and open to new developments. IX 59
- Published
- 1995
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