Body channel communication transceiver design for body area network

Abstract

Recently, body area network (BAN) is getting more and more attention because it provides the wireless communication among the portable devices working around the human body. Body channel communication (BCC) which uses the human body as a communication channel has been concerned as the most power and efficient communication PHY because of the good body conductivity. There were several BCC transceiver studies for healthcare applications which requires high speed communication and entertainment application which requires low power and low speed communication, but those works only focused on either healthcare application or entertainment application. In this dissertation, two BCC transceivers working for both applications are designed while optimizing the energy consumption, power consumption and data rate. In the first transceiver whose code name is Biocle-A, the body channel bandwidth is newly defined by the channel measurement results. Compared with the previous 30 - 120MHz channel, we found that the available body channel bandwidth for portable devices is 20 - 200MHz, so that we can efficiently increase the data rate of the transceiver. The Biocle-A includes two transceivers, healthcare-mode (HC-mode) transceiver and entertainment-mode (ET-mode) transceiver. The HC-mode transceiver adopt the 13.56MHz ISM band with 100kbps data-rate. The R-C oscillator-based super-regenerative transceiver is adopted for ultra-low-power consumption while achieving high selectivity. The ET-mode transceiver has two communication band located at 40MHz and 160MHz, and both bands have 40MHz bandwidth. The following three key building blocks are adopted: 1) sine & rectangular wave modulation dual-band transmitter for high speed communication 2) shared-loop dual-band receiver for low power consumption and 3) on-chip R-C duplexer for full-duplex communication. As a result, we finally achieve 79pJ/b, 80Mb/s, full-duplex ET-mode transceiver and 42.5 $\mu$W power consuming HC-mode transceiver with the Q-factor over 1000. Those two transceivers are implemented in a single chip fabricated in 65nm CMOS process. The second transceiver, Biocle-A2, focuses on improving the pervious transceiver, Biocle-A. The HCmode transceiver adopts the IEEE 802.15.6 standard which was standardized at Feb. 2012 for healthcare application. The cosine wave modulation in the transmitter, the DLL-based BPSK demodulator in receiver and current reusing technique in the received signal strength indicator (RSSI) are adopted for low-power consumption. The ET-mode transceiver adopts the QPSK modulation for better spectrum efficiency. The Biocle-A2 achieves 3.8nJ/b for standard compatible HC-mode transceiver and 90pJ/b, 105Mb/s full-duplex ET-mode transceiver. Those two transceivers are implemented in a Single chip fabricated in 180nm CMOs process.