System considerations for low power design in wireless body area networks

This paper discusses the system level considerations of low-power receivers targeting body area networks (BAN). Since low power consumption is of the utmost importance either OOK or FSK modulation have to be used. We compare the two modulation schemes and compare the system level design issues. Both receivers have a zero-IF architecture and thus have to deal with 1/f noise and DC offsets. The biggest challenge of envelope-detector based OOK receiver design is its poor interferer robustness; the signal-to-interferer-ratio need to be at least 16dB. Additionally the effect of limited ADC ENOB and OOK threshold level on the BER performance of OOK receivers are addressed. On the other hand FSK receivers require a stable local frequency reference which leads to higher power consumption. It can be concluded that in interferer-limited environments FSK receivers are the better choice. Whereas OOK receivers have a slightly lower power consumption.