Estimation of multipath propagation of chaotic radio-pulses in a wireless channel

The characteristics of wireless channel are determined by multipath propagation. The transmitted signal will be scattered so that it produces fading. Fading influenced by multipath component will cause delay spread which damages the signal. Thus, spread spectrum technology is used by using a bandwidth that is greater than the original signal. The objective of this study was to determine the effect of the number of multipath components on orthogonal variable spreading factor (OVSF) codes on multipath fading channels viewed from values and Bit Error Rate (BER) graphs versus Energy Bits per Noise (Eb/No). This study would compare the performance of OVSF code communication system on multipath channels by varying multipath components of 4, 8, 12, 16 and the length of OVSF codes used of 16, 8 and 4. The simulation results showed an increase in BER values when the number of multipath components was added. The more the number of multipath components used, the more the number of reflected signals that will interfere with the desired signal in the receiver. The length of the OVSF code influences the performance of the OVSF code on the multipath fading channel, because each code has a different processing gain value that is affected by the length of the code used

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Industrial wireless channel measurements in a 2.4 GHz ISM radio band using a low-cost SDR-based channel sounder

RECIBE, REVISTA ELECTRÓNICA DE COMPUTACIÓN, INFORMÁTICA, BIOMÉDICA Y ELECTRÓNICA ◽

10.32870/recibe.v9i1.150 ◽

2020 ◽

Vol 9 (1) ◽

pp. E1-1-E1-25

Author(s):

Grzegorz Korzeniewski ◽

◽

Roberto Carrasco Álvarez ◽

Keyword(s):

Software Defined Radio ◽

Communication Systems ◽

Multipath Propagation ◽

Low Cost ◽

Wireless Channel ◽

Channel Measurements ◽

Channel Sounding ◽

Channel Sounder ◽

Radio Band ◽

Mathematical Foundations

Industrial wireless channel is a challenge for the design of communication systems, due to non-Line-of-Sight transmission, caused by the presence of many highly reflective obstacles, and machines in operation, which are a source of the increased noise level. The main effect, which must be analyzed, is multipath propagation. In this article, a low-cost sounding system is proposed, based on Software Defined Radio (SDR) equipment, with the intention of making sounding devices more accessible to a larger group of researchers. Likewise, the mathematical foundations and the software/hardware implementation of the wireless channel sounding system are presented, and the solutions to mitigate the synchronization issues and SDR limitations are also introduced. The performance of the proposed sounder is validated through a measurement campaign in an industrial workshop, considering the 2.4 GHz Industrial, Scientific, Medical (ISM) band. Channel sounding measurements corroborate the accuracy of the results, which converge with the channel mathematical models proposed for several industrial environments and reported in the state-of-the-art literature. In this sense, the proposed channel sounder can be used to investigate the wireless propagation environments.

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Study on Multipath Effect under the Environment of PCM/FM Telemetry Soft Demodulation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.602-605.2298 ◽

2014 ◽

Vol 602-605 ◽

pp. 2298-2301

Author(s):

Gang Fu ◽

Yan Jun Wu ◽

Ren Long Li ◽

Li Ping Wang

Keyword(s):

Detection Method ◽

Multipath Propagation ◽

Signal To Noise Ratio ◽

Wireless Channel ◽

Test Results ◽

Low Snr ◽

Soft Demodulation ◽

Symbol Detection ◽

Signal Crosstalk ◽

Demodulation Method

Because the reentry telemetry wireless channel multipath propagation effects and the effect, channel will introduce transmission time delay dispersion, caused between the PCM/FM telemetry signal crosstalk and signal to noise ratio is too low, significantly increase BER. While traditional demodulation method because the demodulator threshold higher no longer apply. Study the problem, a multiple Symbol Detection method based on sliding strategy (Multi - Symbol Detection, MSD), can effectively overcome the low SNR and inter symbol interference. The simulation and test results verify the effectiveness of the method.

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Blind Fuzzy Adaptation Step Control for a Concurrent Neural Network Equalizer

Wireless Communications and Mobile Computing ◽

10.1155/2019/9082362 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Kayol S. Mayer ◽

Matheus S. De Oliveira ◽

Candice Müller ◽

Fernando C. C. De Castro ◽

Maria C. F. De Castro

Keyword(s):

Neural Network ◽

Radial Basis Function ◽

Basis Function ◽

Fuzzy Controller ◽

Multipath Propagation ◽

Wireless Channel ◽

Constant Modulus ◽

Constant Modulus Algorithm ◽

Radial Basis ◽

Concurrent Architecture

Mobile communications, not infrequently, are disrupted by multipath propagation in the wireless channel. In this context, this paper proposes a new blind concurrent equalization approach that combines a Phase Transmittance Radial Basis Function Neural Network (PTRBFNN) and the classic Constant Modulus Algorithm (CMA) in a concurrent architecture, with a Fuzzy Controller (FC) responsible for adapting the PTRBFNN and CMA step sizes. Differently from the Neural Network (NN) based equalizers present in literature, the proposed Fuzzy Controller Concurrent Neural Network Equalizer (FC-CNNE) is a completely self-taught concurrent architecture that does not need any training. The Fuzzy Controller inputs are based on the estimated mean squared error of the equalization process and on its variation in time. The proposed solution has been evaluated over standard multipath VHF/UHF channels defined by the International Telecommunication Union. Results show that the FC-CNNE is able to achieve lower residual steady-state MSE value and/or faster convergence rate and consequently lower Bit Error Rate (BER) when compared to Constant Modulus Algorithm-Phase Transmittance Radial Basis Function Neural Network (CMA-PTRBFNN) equalizer.

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Экспериментальное исследование многолучевого распространения хаотических радиоимпульсов в беспроводном канале

Письма в журнал технической физики ◽

10.21883/pjtf.2018.16.46476.17392 ◽

2018 ◽

Vol 44 (16) ◽

pp. 48

Author(s):

Л.В. Кузьмин ◽

А.В. Гриневич ◽

М.Д. Ушаков

Keyword(s):

Experimental Investigation ◽

Multipath Propagation ◽

Wireless Channel ◽

Multipath Channel ◽

Signal Delay ◽

Delay Times

AbstractAn experimental investigation of the multipath propagation of ultrawideband (UWB) microwave chaotic radio pulses in a wireless channel has been carried out. Based on the results of measurements, conditions of receiving chaotic radio pulses upon passage via a multipath channel are established for various signal delay times.

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Research on 2.4 GHz Wireless Channel Propagation Characteristics in a Steel Ship Cabin

International Journal of Antennas and Propagation ◽

10.1155/2021/6623638 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Wanli Tu ◽

Hong Xu ◽

Yiqun Xu ◽

Qiubo Ye ◽

Mingxian Shen

Keyword(s):

Wireless Sensor Network ◽

Sensor Network ◽

Multipath Propagation ◽

Signal Propagation ◽

Base Station ◽

Wireless Channel ◽

Field Analysis ◽

Wireless Sensor ◽

Propagation Characteristics ◽

Wireless Signal

Wireless sensor network (WSN) has become a popular technology and has a good potential application in naval architecture and marine engineering field. Analysis of transmission ability of wireless signal in steel ship environment is important for network deployment including base station and node installation, which would directly impact network performance and has become a hot research field. This paper investigates 2.4 GHz frequency wireless signal propagation characteristics in the steel ship cabin. A 3D ray-tracing model of 2.4 GHz wave propagation in the ship cabin is established, a multipath propagation prediction is carried on, and receiving power is calculated. Besides, the experimental test is performed in the real ship. The simulated and experimental results are processed and compared; the influence law of large obstacles on the signal is discussed, and the guidance scheme for node and base station deployment of the wireless sensor network is proposed. The results show that this analysis could provide valid interpretation of wireless channel propagation characteristics in steel ships.

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