Improved two-way double-relay selection technique for cooperative wireless communications

Abstract

In this article, a novel two-way double-relay selection strategy with its bit error rate (BER) performance analysis is proposed. In this novel strategy, as a first step we choose two relays out of a set of relay-nodes in a way to maximize the system performance in terms of BER and complexity. In the second step, the selected relays apply orthogonal space-time coding scheme using the three-phase protocol to establish a two-way communication between the transceivers, which will lead to a significant improvement in the achievable diversity and coding gain with a very low decoding complexity by using a symbol-wise decoder. Furthermore, the performance of the overall system is further enhanced through the use of a network coding method at the selected relay-nodes. Moreover, this paper proposes the analytical approximation of the BER performance. As well, we show that the analytical results match perfectly the simulated ones. In addition, we prove that our strategy outperforms the current state-of-the-art ones by proposing a better cooperative communication system in terms of BER.

Modified artificial neural network based on developed snake optimization algorithm for short-term price prediction

“…Due to the unpredictable nature of the weather, there are many variations in wind generation capacity, which increases the complexity of price forecasting in electricity markets [ [15] , [16] , [17] ]. These changes cause uncertainty in the performance and production of the wind power plant, which must be taken into account by the independent operator of the system to ensure the balance between demand and supply [ 18 ].…”

A Beamforming Technique Using Rotman Lens Antenna for Wireless Relay燦etworks

“…In the recent years, several techniques have been proposed in the field of wireless communications to enhance the error performance of the whole system and its achievable throughput [1][2][3][4][5][6]. A group of these techniques works by increasing or optimizing the transmitted power, while another group is applying powerful forward error detection and correction techniques to increase the achievable gain.…”

“…Later on, several schemes are suggested to improve both diversity order and coding gain by combining diversity techniques with coding algorithms including but not limited to space-frequency coding (SFC) schemes and spacetime coding (STC) schemes [10,[13][14][15]. Furthermore, special diversity techniques using beamforming schemes [11][12][17][18][19] are used to steer the transmitting antenna beams towards the destination terminal to enhance the BER performance and the throughput by maximizing the received signal to noise ratio (SNR), given that the BER performance of the multi-antenna systems suffer from the multiuser interference and channel impairments [1][2][3][4][5][6][7][8][9]. In addition, it is very well known that it is difficult to deploy several antennas at the same mobile station due to several limitations.…”

“…In addition, it is very well known that it is difficult to deploy several antennas at the same mobile station due to several limitations. Therefore, cooperative communication systems can be used to overcome this problem by randomly distributing a group of relay nodes between the two communicating parties [5][6][7][8][9][10][11]20,21]. Those relay nodes can be used in two modes of operation, either to amplify and forward (AF) the obtained signals or to detect the transmitted symbols before forwarding them to the receiving antennas.…”

“…However, relaynodes in wireless relay systems process the obtained signals before transmitting them to the destination terminals by merging the obtained copies of the transmitted signal received via several links to enhance the diversity order and coding gain. These schemes are well known as the spatial-diversity schemes [5][6][7][8][9][10][11]. Lately, several improved relaying methods have been introduced to obtain a high diversity and coding gain.…”