Local frequency offset spatial diversity with pi/4-DQPSK in implant communications

Space diversity reception is well known as a technique that can improve the performance of wireless communication systems without any temporal and spectral resource expansion. Implant body area networks (BANs) require low energy consumption and in some cases high-speed transmission. Therefore, applying spatial diversity reception to implant BANs can be expected to fulfill these requirements. For this purpose, this paper presents a local frequency offset diversity system with π/4-differential quadrature phase shift keying (DQPSK) for implant BANs that offer improved communication performance with a simpler receiver structure, and evaluates the proposal´s bit error rate (BER) performance. We first confirm that the local frequency offset diversity reception can effectively improve the communication performance of implant BANs. We then perform an analysis of a realistic communication performance, namely, a link budget analysis based on derived BER performance and evaluate the link parameters including system margin and maximum link distance. These results demonstrate that the local frequency offset diversity system can realize a reliable communication link in a realistic implant BAN scenario.