Throughput enhancement in cooperative diversity wireless networks using adaptive modulation

This paper analyzes the throughput performance of cooperative diversity wireless networks using adaptive modulation over Rayleigh fading channels. Cooperative diversity is achieved by utilizing neighbouring terminals as relays. These relays can generate copies of the same signal, which can provide spatial diversity gain and signal-to-noise ratio (SNR). The main drawback of cooperative diversity is the throughput loss due to the extra resources needed for relaying. Therefore, throughput is greatly reduced. In this paper, the adaptive modulation is used to convert the obtained SNR gain to throughput gain to compensate for the throughput loss. Results show that the use of adaptive modulation in cooperative diversity networks not only compensates for the throughput loss but also achieves considerable throughput gain compared with the classical system with direct transmission only.