Research on Overlapped Time Division Multiplexing in the Amplify-and-Forward Cooperative Mode

2015 ◽  
Vol 713-715 ◽  
pp. 1103-1106
Author(s):  
Hong Zhang ◽  
Wei Ping Ma
Keyword(s):  
Cooperative Communication ◽  
Gaussian Noise ◽  
Communication System ◽  
Additive White Gaussian Noise ◽  
Spectrum Efficiency ◽  
Amplify And Forward ◽  
Time Division Multiplexing ◽  
Simulation Results ◽  
Time Division ◽  
New System

In order to improve spectrum efficiency of cooperative communication system, Overlapped Time Division Multiplexing (OVTDM) is applied to Amplify-and-Forward (AF) cooperative communication system. The simulation results under Additive White Gaussian Noise (AWGN) channel show that the performance of new system is superior to that of corresponding AF cooperative communication system.

scholarly journals BER Performance Analysis of Non-Coherent Q-Ary Pulse Position Modulation Receivers on AWGN Channel

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6102
Author(s):  
Xianhua Shi ◽  
Yimao Sun ◽  
Jie Tian ◽  
Maolin Chen ◽  
Youjiang Liu ◽  
...  
Keyword(s):  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Theoretical Formula ◽  
Pulse Position Modulation ◽  
Error Performance ◽  
Optimal Receiver ◽  
Awgn Channel ◽  
Simulation Results ◽  
The Relationship ◽  
Better Than

This paper introduces the structure of a Q-ary pulse position modulation (PPM) signal and presents a noncoherent suboptimal receiver and a noncoherent optimal receiver. Aiming at addressing the lack of an accurate theoretical formula of the bit error rate (BER) of a Q-ary PPM receiver in the additive white Gaussian noise (AWGN) channel in the existing literature, the theoretical formulas of the BER of a noncoherent suboptimal receiver and noncoherent optimal receiver are derived, respectively. The simulation results verify the correctness of the theoretical formulas. The theoretical formulas can be applied to a Q-ary PPM system including binary PPM. In addition, the analysis shows that the larger the Q, the better the error performance of the receiver and that the error performance of the optimal receiver is about 2 dB better than that of the suboptimal receiver. The relationship between the threshold coefficient of the suboptimal receiver and the error performance is also given.

Single and Double-Differential Coding in Cooperative Communications

2010 ◽  
pp. 321-351 ◽  
Author(s):  
Manav R. Bhatnagar ◽  
Are Hjørungnes
Keyword(s):  
Cooperative Communication ◽  
Communication System ◽  
Cooperative Communications ◽  
Base Station ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Probability Of Error ◽  
Active User ◽  
Downlink Channels ◽  
Differential Coding

In this chapter, we discuss single and double-differential coding for a two-user cooperative communication system. The single-differential coding is important for the cooperative systems as the data at the destination/relaying node can be decoded without knowing the channel gains. The double-differential modulation is useful as it avoids the need of estimating the channel and carrier offsets for the decoding of the data. We explain single-differential coding for a cooperative system with one relay utilizing orthogonal transmissions with respect to the source. Next, we explain two single-differential relaying strategies: active user strategy (AUS) and passive users relaying strategy (PURS), which could be used by the base-station to transmit data of two users over downlink channels in the two-user cooperative communication network with decode-and-forward protocol. The AUS and PURS follow an improved time schedule in order to increase the data rate. A probability of error based approach is also discussed, which can be used to reduce the erroneous relaying of data by the regenerative relay. In addition, we also discuss how to implement double-differential (DD) modulation for decode-and-forward and amplify-and-forward based cooperative communication system with single source-destination pair and a single relay. The DD based systems work very well in the presence of random carrier offsets without any channel and carrier offset knowledge at the receivers, where the single differential cooperative scheme breaks down. It is further shown that optimized power distributions can be used to improve the performance of the DD system.

scholarly journals Performance Comparison of Digitized Quaternion Modulation with other Modulation Schemes

2019 ◽  
Vol 27 ◽  
pp. 01004
Author(s):  
Anam Zahra ◽  
Qasim Umar Khan
Keyword(s):  
Global Positioning System ◽  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Performance Comparison ◽  
Superior Performance ◽  
Positioning System ◽  
Space Communication ◽  
Global Positioning ◽  
Simulation Results ◽  
Modulation Schemes

In wireless networks signal’s security from noise has been a very challenging issue, primarily because of the broadcast nature of communication. This paper focuses on digitized Quaternion Modulation (QM) which gives better performance as compared to QPSK, QAM and QFSK. We compare the performance of quaternion modulation with other modulation schemes in terms of BER using idealistic Additive White Gaussian Noise AWGN channel. This scheme can be used in applications such as Global Positioning System (GPS), satellite and space communication system to reduce errors. The simulation results show superior performance of the proposed digitized Quaternion Modulation over its counterparts. Thus one may trade off bandwidth for BER.

Parameter Estimation of Co-Channel AIS Signal Using Ambiguity Function

2014 ◽  
Vol 644-650 ◽  
pp. 4035-4039
Author(s):  
Hao Su Zhou ◽  
Jian Xin Wang
Keyword(s):  
Parameter Estimation ◽  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Reference Signal ◽  
Two Dimensions ◽  
Ambiguity Function ◽  
Weak Signal ◽  
Strong Signal ◽  
Estimated Parameters ◽  
Simulation Results

A new data-aided algorithm for parameter estimation of the co-channel AIS signal transmitted over the additive white Gaussian noise channel is proposed in this paper. The co-channel signal consists of a strong signal with high power and a weak signal with low power. The parameters of the strong signal are estimated by searching the ambiguity function of the co-channel signal in two dimensions. A reference signal is therefore reconstructed with the estimated parameters and the aided data. By removing the ambiguity function of the reconstructed reference signal from that of the original co-channel signal, a new co-channel signal ambiguity function is obtained, from which the parameters of the weak signal are estimated. The simulation results illustrate that the proposed algorithm can estimate the parameters of the co-channel AIS signal effectively.

scholarly journals Efisiensi Daya Protokol Quantize and Forward Pada Sistem Komunikasi Kooperatif Multi-relay

2017 ◽  
Vol 13 (1) ◽  
pp. 57
Author(s):  
Nasaruddin Nasaruddin ◽  
Rony Kurnia ◽  
Ramzi Adriman
Keyword(s):  
Cooperative Communication ◽  
Communication System ◽  
Power Efficiency ◽  
High Performance ◽  
Wireless Channel ◽  
Amplify And Forward ◽  
Distance Ratio ◽  
Diversity Techniques ◽  
System A ◽  
Single Relay

One of effective diversity techniques to combat fading on wireless channel is a cooperative communication system in which a source sends information through several relays and then forward it to a destination. A cooperative communication system has shown increased the system performance and reduced the energy consumption. However, it depends on the used relay mechanism that is relay protocols such as quantize and forward (QF) and amplify and forward (AF). In the previous research, energy efficiency of AF relay has investigated for a single-relay cooperative system, but multi-relay is more practical. Therefore, this research focuses on power efficiency in multi-relay cooperative communication system using QF protocol. The research method used is mathematical analysis and computer simulation for outage probability and power efficiency in the multi-relay QF. Simulation result found that multi-relay QF system could provide a high power efficiency, but the efficiency is reduced when the distance ratio increases. Power efficiency can be increased by adding the number of relays in the system. A comparison of power efficiency for QF and AF protocols has simulated, in which power efficiency of multi-relay QF is higher than that of multi-relay AF at distance ratio and power transmit. Thus, multi-relay QF system can provide high performance and power efficiency in the cooperative communication system.

scholarly journals Combined Polar Codes and 2-12 QAM over AWGN and Rayleigh Fading Channels

2021 ◽  
Author(s):  
Flávia Camila Morais Oliveira ◽  
Maria de Lourdes Melo Guedes Alcoforado ◽  
Garik Markarian ◽  
Valdemar Cardoso da Rocha Júnior
Keyword(s):  
Fading Channels ◽  
Gaussian Noise ◽  
Communication System ◽  
Rayleigh Fading ◽  
Additive White Gaussian Noise ◽  
Error Correcting Codes ◽  
Rayleigh Fading Channels ◽  
Modulation Scheme ◽  
Polar Codes ◽  
Qam Modulation

Abstract This article investigates a communication system using polar codes combined with a 2-12 QAM modulation scheme over channels disturbed by additive white Gaussian noise (AWGN) as well as over channels disturbed by Rayleigh fading in addition to AWGN. The 2-12 QAM modulation is compatible with legacy 16 QAM still widely used, and when combined with appropriate error correcting codes produces results that approach the Shannon limit.

scholarly journals Encrypted message transmission in a QO-STBC encoded MISO wireless Communication system under implementation of low complexity ML decoding algorithm

2012 ◽  
Vol 2 (2) ◽  
pp. 53-58
Author(s):  
Shaikh Enayet Ullah ◽  
Md. Golam Rashed ◽  
Most. Farjana Sharmin
Keyword(s):  
Fading Channels ◽  
Gaussian Noise ◽  
Communication System ◽  
Channel Coding ◽  
Signal To Noise Ratio ◽  
Additive White Gaussian Noise ◽  
Text Message ◽  
Low Complexity ◽  
White Gaussian Noise ◽  
Message Transmission

In this paper, we made a comprehensive BER simulation study of a quasi- orthogonal space time block encoded (QO-STBC) multiple-input single output(MISO) system. The communication system under investigation has incorporated four digital modulations (QPSK, QAM, 16PSK and 16QAM) over an Additative White Gaussian Noise (AWGN) and Raleigh fading channels for three transmit and one receive antennas. In its FEC channel coding section, three schemes such as Cyclic, Reed-Solomon and ½-rated convolutionally encoding have been used. Under implementation of merely low complexity ML decoding based channel estimation and RSA cryptographic encoding /decoding algorithms, it is observable from conducted simulation test on encrypted text message transmission that the communication system with QAM digital modulation and ½-rated convolutionally encoding techniques is highly effective to combat inherent interferences under Raleigh fading and additive white Gaussian noise (AWGN) channels. It is also noticeable from the study that the retrieving performance of the communication system degrades with the lowering of the signal to noise ratio (SNR) and increasing in order of modulation.

scholarly journals Outage Probability of Dual-Hop Multiple Antenna Relay Systems with Interference at the Relay and Destination

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Mengmeng Liu ◽  
Jianhua Zhang ◽  
Ping Zhang
Keyword(s):  
Outage Probability ◽  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Multiple Antenna ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Relay Systems ◽  
Single Antenna ◽  
Relaying Systems ◽  
Relaying System

This paper analyzes the outage performance of a dual-hop relaying system in which the relay is equipped with multiple antennas, while the source and destination have a single antenna. New exact closed-form expressions for the outage probability of both the amplify-and-forward (AF) and the decode-and-forward (DF) relaying systems are derived, assuming that the relay and destination are impaired by cochannel interferers and additive white Gaussian noise (AWGN). Numerical results are presented to verify the theoretical analysis.

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