Performance evaluation of an ultra-low power receiver for body area networks (BAN)

Abstract

The main bottleneck to achieve energy autonomy in body area networks (BAN) is the design of an ultra low power yet reliable wireless system. In this paper, we first demonstrate the feasibility of an ultra low power receiver by presenting our implemented receiver chip that could operate on a total power of 479.5 uW, which is more than one order of magnitude lower than commercially available low power transceivers working at 2.4 GHz. We then show the reliability of this chip, which can achieve a receiver sensitivity of -72 dBm for a data rate of 1 Mbps. We further demonstrate that this receiver sensitivity is sufficient to guarantee reliability by evaluating this chip in different to-body communication in BAN environments. By using typical BAN channels, simulation results show that our system can provide a reliable link in both the standing and walking situations. With the measured data, we show that a transmit power of -15 dBm is sufficient for our receiver to achieve reliable communication link in different BAN environments. This transmit power requirement is 15 dB lower than the widely known low power Zigbee system. It could thus significantly facilitate the ultra low power transmitter design, and minimize the human exposure to radio frequency electromagnetic fields. The design and evaluation of our receiver presented in this paper therefore provides a way to move towards the energy autonomy of BAN, and opens access to many new applications in BAN.

A 500mW 5Mbps ULP super-regenerative RF front-end

“…For a BER of 10 -3 , the achieved sensitivity is -67 dBm. The system level measurements incorporating this front-end are presented in [8]. By using oversampling, a sensitivity of -72 dBm is achieved at 1 Mbps with 3 MHz quench rate.…”

Autonomous operation of super-regenerative receiver in BAN

“…It is clear that probability of false alarm should be kept as low as possible to ensure the maximum utilization of spectrum. The probability can be expressed as V. MEASUREMENT RESULTS (4) In this section, we provide the measured spectrum sensing results of a quench waveform calibrated super-regenerative receiver. In the measurement, the chip described in [8] is adopted as the hardware of the super-regenerative receiver.…”

“…A potential candidate to achieve ultra low power wireless communication in BAN is the super-regenerative receiver [4] [5]. However, the main limitation of the super-regenerative receiver is the difficulty in choosing quench waveform to achieve optimum performance, and its relatively poor performance in the presence of interference because of the embedded envelop detector.…”

PPM coding schemes for super-regenerative receivers for autonomous wireless BANs

“…To evaluate the recommended codes for the super regenerative receiver described in [2], a testbed based on a system on chip (SoC) is built up. To emulate an AWGN chan nel, an optical cable which only attenuates signals between the transmit and receive part is used.…”

“…Recommendations of practical code rates follow from computer simulations. In addition, we further emulate our schemes in an implemented ULP super-regenerative receiver shown in [2]. Besides the oretical limits, we also consider practical degradation such as the effect of applying analog-to-digital converters (ADC) with different resolutions in combination with our proposed coding schemes and the non-ideal automatic gain controllers (AGC).…”