Reception Of Ultrawideband Signals Research Articles

ОЦЕНКА ВЛИЯНИЯ ПАРАМЕТРОВ СВЕРХШИРОКОПОЛОСНЫХ РАДИОСИГНАЛОВ НА ХАРАКТЕРИСТИКИ ИХ ПРИЕМА И ПЕРЕДАЧИ

The concepts of the narrowband parameter and the broadband indicator when using ultra-wideband signals are investigated, the main features of signal classification, as well as their advantages and disadvantages are formulated. The influence of the narrowband parameter on the characteristics of emission and reception of ultra-wideband signals is evaluated, and recommendations are formulated to improve the efficiency of their use in radiophysical and electronic applications.

Development of methods and models to improve the noise immunity of wireless communication channels

It has been shown that existing methods and models for improving the noise immunity of communication channels are not capable of meeting requirements for the quality of information in mobile infocommunication systems. In addition, the compromised quality of information fails to protect it and provide the speed of information transmission and density of access channels. It has been proven that reducing the level of electromagnetic radiation is the main method of ensuring noise immunity in wireless mobile communication systems of infocommunication systems. Therefore, one way to ensure the stable interference-free operation is to reduce the level of the information signal at the receiver input to the noise level when the signal/noise ratio is equal to one. This paper reports the results of studying methods and models with correlation reception of ultra-wideband signals. It is proved that according to the level of potential noise immunity, the best indicators are shown by the model of encoding an ultra-wideband information signal by phase manipulation, followed by the coding model with opposite chips, and the code-time manipulation model. It is shown that with a large base of the signal B>300 when the intensity of the received signals is below the level of interference, reliable transmission of information is carried out with a probability of error of less than 10-6. This proves that the use of ultra-wide signal technology allows for wireless hidden transmission of information with low radiation power and a low probability of error. Thus, at a speed of 12 Mb/s, it is possible to chain the transmission of information with a probability of error less than 10-6 if there is a large signal base used, B =500‒1000.

Spiral patch microstrip antenna frequency independent to applications in UWB

A new spiral patch microstrip antenna frequency independent, able to generate a range of frequencies for the transmission and reception of ultrawideband signals, is presented. This antenna operates perfectly with frequencies above 2 GHz without the need for adjustments in its parameters. Measured results have been compared with simulated results and found to be in a good agreement. The spiral antenna produces a remarkable bandwidth to VSWR 2:1. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:861–864, 2014

Enhancement of RAKE receivers for ultra-wideband reception

Ultra-wideband (UWB) is seen as a potential candidate for wireless communication and other applications as it possesses many attractive features. The multipath profile of UWB consists of resolvable components. However, unlike narrow-band pulses, the received components in different directions are fundamentally different from the transmitted signal. Traditionally, RAKE receivers work by correlating the received signal with the source signal. Although this proved sufficient in the narrowband transmission, it is not the case for the wideband. Some researchers showed that significant improvement in captured energy (CE) in the wideband reception could be achieved by correlating the received signal with multiple received templates. The author re-visits the issue to assess the amount of improvement resulting from multi-template reception of UWB signals and its relation to the number and type of templates. Moreover, the author studies the cost of the multi-template reception. Finally, a threshold-based capturing technique that reduces the cost of reception while maintaining most of the attainable gain in CE is proposed.

On Rake Reception of Ultra Wideband Signals over Multipath Channels from Energy Capture Perspective

Performance of Rake reception of Ultra Wideband (UWB) signals is evaluated from energy capture perspective. In addition to ordinary all Rake (ARake) and selective Rake (SRake) receivers which are considered in conventional spread spectrum communications, we introduce optimum ARake and SRake receivers which include the estimation of delay of the combining multipaths. Impact of pulse-width is discussed on their performances considering the relationship between pulse-width and fading. Time hopping M-ary pulse position modulation (TH-MPPM) and binary phase shift keying (TH-BPSK) are considered as modulation schemes. Extensive simulation results are presented showing the performances of the Rakes introduced using IEEE 802.15.3a UWB channel models (CM1 to CM3). Performance of MPPM is shown for various values of M and modulation parameters. The impact of pulse-width is illustrated mainly using BPSK. It is shown that the total energy capture (i.e. by ARake) strongly depends on the pulse-width, and the shorter the pulse-width the more is the amount. The energy capture also varies a lot for employing either optimum or ordinary Raking method. Energy capture by SRake additionally strongly depends on the number of combined paths until the number is ≤ 20 for optimum SRake and ≤ 10 for ordinary SRake; however, afterwards saturating effects are seen. Several aspects regarding the performance versus complexity issue of Rake receivers are also discussed.