Using Pulse Width Modulation for Wireless Transmission of Neural Signals in a Multichannel Neural Recording System

Abstract

This paper presents a wireless implantable neural recording system (WINeR), which pulse width modulates (PWM) a 15-channel time division multiplexed (TDM) neural signal for telemetry in the industrial-scientific-medical (ISM) band. To evaluate the performance of this wireless PWM-based architecture and indicate its potential sources of error, measurements have been conducted on a setup consisting of the WINeR system as the transmitter and two receivers: 1. An Agilent 89600 vector signal analyzer with 36 MHz bandwidth and 2. A custom built receiver with bandwidth of 75 MHz. In addition, a MATLAB-Simulink model of the entire WINeR system is constructed to simulate the overall behavior of the system. We concluded that the WINeR chip, fabricated in a 0.5 mum standard CMOS process, can acquire and wirelessly transmit up to 320 k samples/sec to a 75 MHz receiver with 8 bits of resolution, equivalent to a wireless data rate of 2.56 Mb/s.