Design and performance analysis of PSPK modulation for WBAN

WBAN means short-range wireless technology that intra body or adjacency of body. WBAN standard group (IEEE 802.15. TG6) are define the WBAN system technical requirements. The scalability of data rate, power consumption and system complexity are important for in-body communication systems. The implant device requires low data rate, but capsule endoscope and bionic eye with HD image transmission device require high data rate. In addition, implant device has to maximize the power efficiency, because the system with a small sized battery inside the body should persist for a long time, and the battery is not easy to change. For this reason the PSSK(phase-silence-shift-keying) modulation proposed scalability of data rates and reduced system complexity. This method needs double of bandwidth than PSK modulation, but SER performance is about 6dB better than PSK at SER 10^-6. They proposed PSSK modulation for the in-body communication systems because FSK modulation requires wide bandwidth for transmission high data rates. In this paper, we propose a new PSPK modulation scheme to reduce the power consumption. The new PSPK modulation method needs a double portion of bandwidth more than existing PSSK modulation. The existing M-array PSSK, one bit determines the silence-envelope position of the symbol, and (log₂M)-1 bits determine the phase of symbol. This method is able to modulate by using 2 kinds of QPSK. The proposed PSPK lowers the bandwidth efficiency by half than the existing PSSK, but BER performance is better than existing PSSK.