Yuan Gao; San-Jeow Cheng; Wei-Da Toh; Yuen-Sam Kwok; Tan, K.-C.B.; Xi Chen; Wai-Meng Mok; Htun-Htun Win; Bin Zhao; Shengxi Diao; Cabuk, A.; Yuanjin Zheng; Sumei Sun; Minkyu Je; Chun-Huat Heng, "An Asymmetrical QPSK/OOK Transceiver SoC and 15:1 JPEG Encoder IC for Multifunction Wireless Capsule Endoscopy," Solid-State Circuits, IEEE Journal of , vol.48, no.11, pp.2717,2733, Nov. 2013 doi: 10.1109/JSSC.2013.2274894 URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6581923&isnumber=6642065
Abstract:
This paper presents a chipset including an asymmetrical QPSK/OOK transceiver
SoC and a JPEG image encoder for wireless capsule endoscopy. The transceiver SoC
supports bi-directional telemetry for high data-rate image transmission with QPSK
modulation and low data-rate command link with OOK modulation. A low power JPEG
encoder is designed to compress raw image data with compression ratio as high as 15:1 using
sub-sampling technique in YUV color plane. Implemented in 0.18 μm CMOS, the QPSK TX
consumes 5 mW at –6 dBm of output power with 3 Mb/s data rate while the OOK RX
achieves –65 dBm of sensitivity at 500 kb/s data rate with 4.5 mW power consumption. A
prototype capsule has been implemented with the chipset and the performance has been
verified with in vivo animal experiment. With duty cycling, the average power consumption
of TX is 2.5 mW when transmitting at 3 fps frame rate.
Index Terms— Wireless capsule endoscopy (WCE), transceiver, quadrature phase-shift
keying (QPSK), OOK, JPEG