Open AccessDual‐hop signal space cooperative systems using multiple DF relays
Author(s) -
Khan Muhammad Ajmal,
Rao Raveendra K.,
Wang Xianbin,
Sheikh Asrar
Publication year - 2016
Publication title -
iet communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.355
H-Index - 62
eISSN - 1751-8636
pISSN - 1751-8628
DOI - 10.1049/iet-com.2016.0372
Subject(s) - relay , computer science , hop (telecommunications) , rayleigh fading , spectral efficiency , transmit diversity , fading , cooperative diversity , diversity gain , transmitter power output , topology (electrical circuits) , algorithm , telecommunications , channel (broadcasting) , mathematics , power (physics) , physics , transmitter , quantum mechanics , combinatorics
In a dual‐hop relaying system without a direct link between the source and the destination, the source broadcasts information signal to the relay and relay broadcasts it to the destination, thus it uses two phases to transmit one symbol. This study proposes a novel scheme to incorporate signal space diversity into a dual‐hop relaying system with multiple decode‐and‐forward (DF) relays to enhance its spectral efficiency. The proposed dual‐hop signal space cooperative relaying scheme transmits two symbols in three phases while the conventional dual‐hop DF relaying system uses four phases to transmit the same two symbols. Therefore, the proposed scheme improves the spectral efficiency without additional complexity, bandwidth or transmit power. The proposed scheme is analysed over Rayleigh fading channel and error probability performance is derived. Moreover, an asymptotic approximation for the error probability is obtained to illustrate the impact of different system parameters and diversity gain. In addition, this study discusses the power allocation optimisation, relay position optimisation and the joint optimisation of both. Furthermore, closed‐form expression for the average channel capacity is derived. In the end, analytical results are compared and validated through Monte Carlo simulations.