Doppler Compensation Based Optimal Resource Allocation for QoS Guarantees in Underwater MIMO-OFDM Acoustic Wireless Relay Networks

Currently, the multiple-input-multiple-output (MIMO), the orthogonal frequency division multiplexing (OFDM), and relay technology have played a major role in radio-frequency (RF) communication networks, which have significantly improved the RF wireless network performance, such as spectrum efficiency, bit error rate (BER), and delay bound guarantee, etc. Based on their wide and crucial applications, we can also apply these advanced technologies into underwater acoustic wireless networks. However, due to the harsh underwater environments, dramatic water-wave dynamics, and the network nodes´ mobility, there is serious Doppler shift problem for underwater wireless networks, which can result in inter-carrier interference (ICI). In order to remedy the effect caused by the Doppler shift, we propose the Doppler compensation resource allocation scheme for QoS guarantee in underwater MIMO-OFDM acoustic wireless relay networks. Our goal is to maximize the entire network throughput while guaranteeing the QoS requirements for multimedia applications over MIMO-OFDM acoustic wireless relay networks. Simulation results obtained show that our proposed Doppler compensation based optimal power allocation scheme for underwater MIMO-OFDM wireless relay networks outperforms the other existing scheme without Doppler compensation in terms of maximizing the capacity while satisfying all wireless links´ bit-error-rate QoS requirements.