A hybrid OFDM body coupled communication transceiver for binaural hearing aids in 65nm CMOS

An interference and multipath resilient Body Channel Communication transceiver with ground effect cancellation for binaural hearing aids application is presented. The channel characteristics are measured between the intended points of transmission and reception to measure the path loss. The energy efficient transceiver is based on Hybrid OFDM folded in FSK modulated signal to mitigate the multipath problem in binaural hearing aids. By eliminating the needs for DACs, ADCs and power amplifier, the proposed design is free from peak-to-average power ratio (PAPR) problem. It utilizes 4 channels Adaptive Frequency Hopping technique for resisting interference. A variable gain LNA is exploited in this implementation to overcome the variable ground effect of BCC. The transceiver is implemented in 65nm CMOS process with an active area of 2.28mm² for baseband OFDM and a data rate transmission of 1 Mbps while consuming 1.54mW.