11 Mbps high data rate MICS band (402-405) QPSK data transceiver system for the implementation of low-power biomedical implant devices

This paper presents modeling and simulation results of a custom model for high data rate wireless quadrature phase shift keying (QPSK) data transceiver system. It will be used in the medical implant communication system (MICS) for a biomedical implant devices. The MICS is a low-power, short-range (<2 m) and high data rate communication band (core band: 402–405 MHz) accepted worldwide for transmission of data associated with a medical implant device. The output of the analog-to-digital converter (ADC) is taken as the input of the transmitter and modulated by a direct QPSK modulation scheme with the MICS frequency band (center frequency: 403.5MHz). The modulated data are transmitted through a near tissue skin channel, designed according to the IEEE 802.15.6 standard (CM2 scenario) with a reference distance of 50 mm with data rate of 11 Mbps. Due to the higher spectral efficiency requirement and lower power consumption, the QPSK modulation scheme is considered for system level design. The performance of the overall system was evaluated in term of signal-to-noise ratio (SNR) versus bit error rate (BER) and channel capacity in term of cumulative distribution function (CDF). Target BER of 10-3 is achieved at SNR 11 dB that satisfies the required characteristics of MICS implant devices at a higher data rate of 11 Mbps. The highest data rate is achieved with the transmitting power 25uW. The receiver sensitivity and path loss variation are determined according to the distance and energy consumption per bit.