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This article discusses the features of the noise immunity of short-pulse ultra-wideband (UWB) radio systems in indoor operation (INDOOR). Such a mode of operation of UWB radio systems has pronounced features that are associated with multipath propagation of a signal inside a room. The principles of modeling the UWB radio communication channel indoors are considered, the results of the influence of the environment on the UWB signal are given, an analytical expression is obtained for calculating the error probability of the UWB radio system when operating indoors with multipath propagation.

currently, optical motion capture systems are widespread. The natural desire to create a cheap and accurate system leads to the search for new technical solutions. One of the promising areas are ultra-wideband technologies, the current level of development of which allows them to be used to solve this problem.

The article describes modern approaches to the choice and synthesis of modulating functions used for various purpose radio system signal generation.

In the article based on the probable model [1], a method is proposed to reduce the probability of incorrect data reception in radio channels of terahertz radio spectrum, which will provide an optimal choice of frequency ranges or transparency windows. Depending on the requirements of the necessary applications, it is possible to make a rational choice of radio system parameters that will meet the criteria for bandwidth and range of these applications.

In this article a brief description of a direct conversion receiver is given, sources of affected channels in such a receiver are examined. Practical methods for eliminating of affected channels of a real radio system are proposed.

More than half of the mobile backhaul connections are wireless and huge capacity promise of mmW bands is compelling to cope with the increasing data capacity for future 5G system. We reported a backhaul E-band measurement campaign focusing on radio system measurements with the demonstrator developed in the project. The evaluations include the throughput measurement with different modulation coding scheme and hop length in LOS scenario and the link performance in the light obstructed LOS. It is reported that 1 Gbit/s could be supported up to 300 m, and a reliable transmission was possible up to 400 m at the minimum throughput. The accuracy of beam alignment has been evaluated and it could be improved with the help of electrical beam switching function.

In this paper we present a survey based on vast res earch done in the area of various important factors relating to full duplex communication revealing several facts. In fact thes e revelation has served to be vital in the future d esign of any full duplex communication system . The major problem or challen ge faced in such a system was the interference caus ed from the transmitting antenna on the receiver antenna placed at the same node. The interference was termed as ' self interfe rence'. Wireless transceivers nodes can select between transmit and receive funct ions on the same frequency band at different time ( Time Division Duplex-TDD) or they can transmit at the same time at different frequencies ( Frequency Division Duplex-FDD). Recen tly researchers have put forth a new radio system, that can operate full duplex ov er a single channel , that is transmitting and rec eiving at the same time on the same frequency band. This kind of system is overwhe lmed by interference. Interference need to be redu ced to the point where the receiver can detect even the weakest signal of inte rest. Several active interference cancellation tech niques that can help in self interference reduction have been proposed. The in d epth survey was helpful enough to come out with a n ovel solution to an antenna design based on passive suppression techniques usin g polarization and other diversity techniques so a s to reduce the self interference problem.

In this letter, over-the-air (OTA) tests of the performance of the IEEE 802.11p radio system are performed in a reverberation chamber (RC) that is equipped with a fast rotating mode stirrer. By varying the speed of the mode stirrer, different levels of Doppler spreads are created, and the 802.11p radio system is tested accordingly. As expected, the Doppler spread affects the package error rate (PER) of the radio system adversely. In addition to measurements, a simple PER model is presented, which sheds some light into the OTA tests.

A Cognitive Radio (CR) is a reconfigurable radio system, consisting of both hardware and software. The presence of hardware entails implementation of Electromagnetic Interference (EMI) protection and also resolution of Electromagnetic Compatibility (EMC) issues. It is of paramount importance that these aforementioned aspects are dealt with correctly by proper design in multi-transceiver CR networks, so as to negate performance degradation or complete loss of communication. Both generic methodologies of ensuring this aim as well as applicable standards that may be tailored for this application are discussed. Details of a measurement setup that may be utilized are also briefly elucidated in this paper along with simulation results.

The article examines the processes in radio-electronic systems consisting of multiple various radio devices that experience intentional and unintentional intentional interference. The research is aimed at finding the optimal plan for the operation of multiple radio-electronic devices so as to increase the efficiency of joint performance by means of readjusting the parameters of radio waves.

Software-defined radio requires the combination of software-based signal processing and the enabling hardware components. In this paper, we present an overview of the criteria for such platforms and the current state of development and future trends in this area. This paper will also provide details of a high-performance flexible radio platform called the maynooth adaptable radio system (MARS) that was developed to explore the use of software-defined radio concepts in the provision of infrastructure elements in a telecommunications application, such as mobile phone basestations or multimedia broadcasters.

A proposition for a new empirical propagation model, in the form of four formulas appropriate for characteristic types of the urban environment, is outlined. A measurement verification of some well-known models and specification of the propagation environmental are first described. Taking into account about nineteen thousand measurement cases, a new model obtained by multidimensional regression analysis is than presented. Finally, the practical usefulness of the model for radio system design analysis is discussed.

This session features numerous low-power wireless techniques and systems to address the challenges of IoE. Presented are an ADPLL-based hybrid-loop BLE receiver, an ultra-low-power receiver using transmitted reference modulation, a fully digital IEEE 802.11ah-compliant polar transmitter, an ETSI Class-1-compliant IoE transceiver, a GNSS receiver aimed at IoE applications, a Filtering-by-Aliasing receiver, a syringe-implantable radio system on glass substrate including antenna, a BLE-compliant wake-up radio and an N-path switched-capacitor-based transceiver.

Indoor localization systems have been used in many divers application of commercial, public service and military sectors. This paper presents a proposal of system for ultra-wideband (UWB) radio system allowing Real Time Localization (RLTS) in indoor environment. Accurately tracking people in indoor locations is a very difficult technical problem that has not yet been completely solved. UWB transmission technology is primary attractive in GPS denied environments such as buildings. In this paper will be described important parameters of ultra-wideband radio system that depends on complicated conditions especially in buildings. Another goal of this paper is to examine the basic positioning principle and various approach of realizations of UWB systems which would be used for tracking people in complex indoor environments. This application has been recently researched in many scientific papers and experimentally studied. The UWB localization system is especially suitable in this context because it allows centimeters accuracy in ranging, as well as low-power and low-cost implementation.

Emerging approaches to HF communications aim to increase the range of missions and applications HF can support by using higher bandwidths to achieve higher on-air data rates and/or improved communications robustness. Current proposals achieve this in either of two ways: by (i) increasing the bandwidth allocated to a single-carrier modulated waveform, to up to 24 kHz (or possibly higher), or (ii) using existing modulation formats to simultaneously modulate up to 16 carriers in noncontiguous 3 kHz channels. Each of these approaches has inevitable consequences for both radio system performance and spectrum utilization and availability. Both the US Department of Defense and NATO have standards documents (respectively, MIL-STD-188-141C and STANAG 4203) intended to specify the performance and spectral occupancy characteristics of military HF radios. However, these standards have been primarily focused on operation on traditional 3 kHz channels, and do not fully address either of the two proposed Wideband HF (WBHF) approaches. This paper analyzes some key performance impacts of the two WBHF approaches, uses a simple system model to predict the spectrum occupancy and efficiency of the two approaches, and provides recommendations for new and revised requirements to address Wideband HF systems in the applicable US and NATO standards.

The rejection of QPSK interference in a THPPM UWB system using complex adaptive filter and a nonlinear correlation receiver (NCR) with a soft-limiter will be considered in this paper. This system brings a significant performance improvement compared to the system which uses complex adaptive filter and a linear receiver, particularly in the case of high interference power, where its absence leads to the reception loss.

For non-coherent detection based cognitive radio (CR), the required length of the spectrum sensing window is inversely proportional to the primary user’s (PUs) signal strength. When a CR system’s transmission period is fixed, the length of the CR’s transmission window can be inadequate to fully utilize the white space if the corresponding PUs operate in low-SNR regime. We propose a sensing window optimization algorithm in this paper aiming at improving the spectral efficiency of the cognitive Ultra Wideband (UWB) radio system. The proposed algorithm can find the optimal tradeoff between the sensing window length and the desired detection probabilities for the UWB based CR system in low-SNR regime. Compared with the conventional sensing algorithms in which the sensing window is fixed, the proposed algorithm can significantly increase the length of the CR-UWB’s transmission window so as to use the available spectrum more efficiently while guaranteeing the PUs’ operation.

This paper presents a method of predicting the bit-error rate (BER) performance of the global system for mobile communications (GSM) system as a function of the wideband channel parameters obtainable from measured or assumed power delay profiles. Although delay spread is found to be the most useful parameter for the prediction of BER performance, it has been shown that in some conditions delay interval (15 dB) can provide a more accurate prediction mechanism. Thus, based on the delay spread and the delay interval (15 dB), empirical prediction formulas are derived.

Cognitive Radio (CR) is an intelligent radio system, which is capable of being aware of the communication environment and consequently adapts to it. With Null Broadening (NB) technique, CR can share the spectrum and coexist with licensed users (LU) by displaying nulls to a certain range of Direction of Arrival (DOA) of LU. In this paper, we present a new CR downlink beamforming method via combining filtering and NB techniques together, which enables CR to broaden and also deepen the nulls towards LU directions. Meanwhile, it also enlarges the width of the main beam to tolerate the DOA ambiguity of CR users. After employing the proposed method, CR directs the main beam towards its own users while putting deeper and wider nulls to the LU in the downlink beamforming. The proposed beamforming scheme causes less interference to LU while sharing the same spectrum.

This paper presents a design of radio systems for capsule endoscopy operating in the 400 MHz band. The design is conducted through estimating a link budget based on system requirements and limitations for the radio systems. In order to calculate the pathloss accounted in the link budget, a method to estimate the pathloss is introduced that brings a patient-specific pathloss model. This method allows calculating the pathloss estimates between the capsule device in the small intestine and on-body antennas. The results show that the use of an antenna diversity technique is crucial to increase the channel signal-to-noise ratio (SNR) in capsule endoscopy. Also, the location onto which the on-body antennas are attached is important to bring the diversity gain.

Spread-spectrum modulation can be used in a radio system to reduce the likelihood of intercept, as well as providing some protection against jamming and interference. These antijam, anti-interference and low-probability-of-intercept properties are highly desirable in secured communication systems. In addition, spread-spectrum techniques have been proposed to combat spectral congestion by improving the efficiency of spectrum utilisation. Spread-spectrum techniques are also widely used in ranging systems and in local-area networks (LANs) or other multiple-access systems. In the present article, the three main spread-spectrum techniques are outlined and then applications of frequency-hopping systems and some of the techniques used are described.

This paper presents system-level modelling of potential multiband orthogonal frequency division multiplexed ultra wideband (UWB) system. System performance is measured using bit error rate (BER) and signal-to-noise ratio. The conducted system analysis demonstrated that the BER is equal to or less than 0.1%, for 75% of stable (i.e. transmitter is on waist) and 61% of unstable transmitter locations (i.e. transmitter is on wrist) respectively. This demonstrates promising applications of the proposed UWB body-centric radio system.

Measurement-based methods for the reassignment of a call to another time-slot with less cochannel interference on a time-division multiple access (TDMA) radio link are described and evaluated using a discrete-event simulation. Portable radio access, transfer triggering, and time-slot selection are modeled using an integrated radio and traffic call model. Results showed that link quality can be maintained with a low transfer rate, even under busy conditions. Regeneration of transfers was minimal. Performance was robust with respect to trigger measurement error, whereas the dynamic range of transmission quality measurement was found to be more critical in maintaining quality. Hysteresis reduced the rate of time-slot transfer while only minimally affecting quality. >

This work will address the challenges to facilitate the development of a high capacity radio system for a small, miniaturized electronic pill device that can be swallowable or implantable in human body in order to detect biological signals or capture images that could eventually be used for diagnostic and therapeutic purposes. In addition to reviewing and discussing the recent attempts in electronic pill technology, a wideband (UWB) telemetry system aimed for the development of an electronic pill will be presented in this paper. We have successfully realized more than half a meter UWB link under conditions emulating an implant

This paper will examine the subtle interdependencies of physical layer waveforms and RF power amplifiers when applied to a battery-powered tactical radio system. Traditional physical layer analysis usually compares the signal-to-noise ratio (SNR) required to achieve a desired bit error rate (BER) but does not consider how the peak-power to average-power ratio (PAPR) of the waveform will affect the design and performance of the power amplifier. This paper will address both the BER performance of physical layer waveforms and the class/efficiency/power constraints of power amplifiers for use in a battery-powered tactical environment.

This paper describes the dynamic spectrum access radio system that was built as part of the DARPA XG program. The DSA system's architecture four principal components (the DSA engine; the environmental sensing (i.e., detection) subsystem; the communications (i.e., radio) subsystem; and a policy module/enforcer) are described. The DSA system's 802.16-based radio hardware is described. One of the field tests related to group sensing is described. A companion paper describes the XG DSA policy software design and field test.

This paper presents our recent works on wideband planar antennas for quasi-millimeter-wave (22-29 GHz) ultra-wideband (UWB) radio system and 60 GHz-millimeter-wave wireless system such as millimeter-wave (MMW) wireless personal network (mmWPAN).

In this paper we present a flexible MIMO-OFDM system concept for research purposes. Algorithms for multiplexing pilot tones into MIMO-OFDM signals are reviewed. A general formulation for using orthogonal pilot sequences that extent across multiple OFDM symbols is given. Simulations are carried out to evaluate the performance of the algorithms. Transmissions are performed on a MIMO laboratory system in an indoor LOS (line of sight) environment with various parameters to validate the useability of the proposed concept.

This paper presents a brief review and recent development of ultra-wideband (UWB) filters for microwave UWB radio system (from 3.1 to 10.6 GHz) using broadside-coupled structures. Design considerations and requirements for such UWB filters to meet the UWB regulation are described. Several recently developed UWB filters, including full FCC UWB bandpass filter, UWB lowpass filter, notch-band implemented UWB bandpass filter for avoiding interference, and a super UWB filter with wider bandwidth than conventional UWB system are demonstrated.

This paper presents a low-power low-noise amplifier (LNA) with switching bands for MB-OFDM Group-C and Group-D ultra-wideband wireless radio system. The LNA is designed and implemented in TSMC 0.18 mum . Simulation results show that power gain of 12.4 dB, input and output matching lower then - 8.5 dB and - 14.5 dB, and a minimum NF of 4.0 dB can be achieved, while the power consumption is 11.2 mW through 1.8 V power supply.

This paper presents a low-power low-noise amplifier (LNA) with switching bands for MB-OFDM Group-C and Group-D ultra-wideband wireless radio system. The LNA is designed and implemented in TSMC 0.18um RF CMOS process. Simulation results show that power gain of 12.4 dB, input and output matching lower then -8.5 dB and -14.5 dB, and a minimum NF of 4.0 dB can be achieved, while the power consumption is 11.2 mW through 1.8V power supply.

Detect and avoid procedures (DAA) aim at improving ultra-wideband (UWB) coexistence with narrowband-wideband devices operating at the same time and in the same area. UWB is commonly considered as a secondary radio system. As a consequence interference due to UWB has to be kept under control. To this aim it was shown that by properly tuning DAA parameters UWB interference could be kept below the limits issued by regulatory bodies. Non-cooperative DAA procedures can lead to severely reduced performance of UWB networks. The possibility of integrating UWB devices on the same board of the victim device has opened the way to the definition of more efficient DAA procedures, indicated as cooperative DAA, guaranteeing better coexistence performance as well as an improved UWB throughput. In this paper we present a cooperative DAA procedure and we compare its performance with the non-cooperative one under the same operating scenario. It is shown that the DAA procedure can significantly outperform the non-cooperative DAA.

This paper describes a low complexity, low data rate ultra-wideband system suited for use in body area network (BAN) applications. The described system has lower complexity and power consumption compared to similar systems for BAN applications. System architecture is defined and expected results in BAN communication channel are presented. Main building blocks like analog RF front-end IC and small size antennas suitable for applications on the human body have been developed and produced. Some measurement results of the implementation are presented.

A compact radio system module, 10/spl times/10.3/spl times/1.2 mm/sup 3/, for triple-band GSM cellular phones is presented. The module was miniaturized by employing a simple front-end architecture, highly integrated transceiver IC, one chip HPA-MMIC, and thin four-layer laminate substrate. Design considerations for a very compact radio system module, i.e., techniques for avoiding thermal and electrical interaction, are discussed. The excellent performance of the developed module, which is reflected in its high thermal and electrical isolation, is demonstrated.

This paper details the implementation of a complete radio system for both 2.4 GHz and 868/915/433 MHz in a 0.18 micron standard CMOS process. Topics explored include a brief market requirement analysis of standards such as Bluetooth and Zigbee vs. optimally designed devices. Such devices are typically employed in ultra-low cost ( < $1), low-power designs and the governing factors and influences of this shall be discussed. The basic architecture of the Nordic Semiconductor nRF2401 and nRF905 and the ability to implement additional digital functionality of a radio system in the CMOS process is presented. Key system functionality and performance is covered.

The experimental approach is taken. We discuss some of our latest results on MIMO radio system characterization in order to give insight into the effect of typical cellular propagation channels and especially mobile antennas on the performance of MIMO systems.

Nowadays, radio system transmitter (Tx) harmful interference and radiation effects are significantly important and complex. A very important issue is the requirement for coexistence of transmitters (Tx) and receivers (Rx) on the same site (cosited), where radio mutual interference and radiation hazards are significantly more important than from internal, natural and industrial noise effects. Results show that under some cosited scenarios when victim Rx are blocked or strongly desensitized by high power interfering Tx. Persons located in the proximity of the Rx may be affected by radiation intensity which may approach the standard threshold limits. Thus, we can conclude that in special cases, described in this paper, a correlation exists between Tx's interference to victim Rx and radiation intensity level to exposed human. However it is important to emphasize that the sensitivity of Rx to Tx high power interference is significantly higher than the sensitivity of exposed people to radiation effects.

History, theoretical concepts, and technical features are included in a summary of radio communications by means of the scattering mechanism in the troposphere. Common radio system configurations and methods of predicting radio transmission parameters are discussed. Analog system performance and a method of analysis is included. The implicit diversity effect and reduction of intersymbol interference in digital system implementations are also presented. Keywords: tropospheric scatter radio; troposcatter; radio communication; adaptive equalizer; transmission loss prediction

The influence of an antenna directional properties on the EMC condition of a radio link is discussed. First, taking into account the functionally form of a radio link structure, the EMC aspect due to the directional properties of different antenna types, which is used in practice, is presented. Next, the principles of an antenna choice which are recommended for radio system planning procedure of the fixed and mobile radio link are described. The EMC problem of the cellular mobile radio network and the EMC properties of an adaptive antenna are analysed too.

A qualitative analysis is presented of mutual interference arising when two perfectly shielded transceivers, sited at the same location, are operating simultaneously. The restrictions imposed on the antennas for achieving reliable operation of a third remote system victim receiver are also considered. In addition, some recently developed semiempirical, computer methods are discussed that allow the mutual interference factors affecting several worst-case scenarios to be computed. These computed results are then used to check design modifications and to improve system operational performance, including frequency management. >

An examination is made of the performance deterioration of multiple-access radio systems using spread spectrum modulation due to the presence of colocated or cosited interferers. Cositing interferers are simulated with a general-purpose computer program. Effects of colocation interference are measured using a radio prototype. For the particular radio system under consideration, it is concluded that a frequency management that allocates different carrier frequencies to radios in the vicinity of a receiver, is necessary only for radios in colocation. The radio system is fairly robust with respect to radios in cositing. >

The authors analyze the performance of a multicarrier modulation system with signal transmission during a guard period. They derive the bit error rate (BER) performance of the multicarrier modulation system under time and frequency selective fading environments. The relations between irreducible BER performance and the number of subchannels are shown. Next, they propose a subchannel assignment protocol that provides a variable-bit-rate transmission capability. This protocol provides better packet loss probability and throughput performance than the conventional frequency division multiple access (FDMA) protocol. >

A novel WDM fiber radio system with improved spectral efficiency, incorporating remote LO delivery and novel FBG optical filtering techniques is demonstrated. All channels within a 25 GHz band are successfully recovered with minimal degradation.

To provide performance of radio system when interfering influence, the devices of adaptive cancellation of radio interferences are widely used. This work presents an approach to estimation of the adaptive frequent filter selectivity in view of massive and random interfering influence on it. This approach is based on the methods, statistical theory of EMC provided. Probability of interference penetration through the filter was used as the criterion to selectivity estimation.

In the proposed picocellular radio system a microwave reference and subcarrier multiplexed radio signals are distributed optically. The millimeter-wave carrier is generated by phase locking technique. This approach is not affected by dispersion and utilizes inexpensive devices.

We describe the merits of a software tool based upon the statistical Monte Carlo technique which is capable of analysing complex radio system compatibility issues. The tool can be used to help spectrum engineers make the most efficient use of the limited radio frequencies available. It is able to help identify candidate frequency bands for radio systems; determine the appropriate size of guard bands; derive transmitter emission masks needed to protect adjacent services; specify receiver susceptibility to preserve system performance in a given radio environment; identify band sharing issues between different services and technologies and provide smooth band re-farming strategies. A description of the tool is provided as well as an explanation of its applicability. In addition there are a number of examples illustrating the usefulness of the tool.

Microcellular structures are employed in order to maximize the spectrum efficiency of the radio system. Previous studies and measurements have examined a cell shape in urban areas with rectilinear streets in the form of a squared diamond with four tails that introduce overlapping coverage among the cells. The effect of this overlapping on the performance of the urban microcells is addressed. Stochastic analysis and simulation are used to quantify the effect of overlapping on the performance measures. The results demonstrate the improvement in the teletraffic performance measures and the resultant degradation in the signal-to-interference ratio, S/I.