An Implementation Of A Transciever For WBAN

With the rapid development of semiconductor industry wireless communication system for human health applications have emerged to meet the demands of our aging population. Wireless Body Area Network(WBAN) has attracted a number of researchers both from the academia and industry in recent years while the concept of WBAN was suggested in 1996 and the IEEE 802.15.6 standards was established formally in 2012. This paper is mainly about the design of reciver and transmitter refering to the WBAN standards and the relevant aplications in Occident and Japan.With the feature of low attenuation when the signal transfer within the human body compared with the higher frequency bands, 400 MHz frequency band is designed for medical implants communication. In this article, a transceiver is designed covering the 400 MHz to 450 MHz after the comparision of all the PHY layers of WBAN.The standard requires the transceiver covers from 400 MHHz to 450 MHz while the bandwith of each channel is 1MHz and data rate can range from 50 kbps to 150 kbps. The main modulation techniques include DBPSK, DQPSK and MSK. The transmitter shall be capable of transmitting at least 0dBm EIRP and the adjacent channel power ratio should be lower than-26 dB meanwhile the EVM value ranges from-20 dB to-11 dB warying depending on the modulation teniques. The sensitivity of the receiver which can handle input power between-90 d Bm to-40 dBm is about-84~95dBm, and the adjacent channel rejection should be higher than 6~17dB while the SNR of the output signal of receiver is 12 dB.We choose the low-IF architechure enventually after the article lists the varity of receiver and transmitter structure, and their benefits and drawbacks. 2MHz is selected as the IF signal compromise between the frequency band selection and channel selection.As the transceiver belongs to narrow band system for it covering 400 MHz to 450 MHz, so we can make the best of the inductor source degradation structure. A double-balanced active structure is adopted as the mixer for it can improve the linearity of the system and the elimination of even-order harmonic distortion. After down-converted to I/Q signal, the IF signal flow through complex filter and amplified by PGA to such an extent that can drive the ADC. The complex filter bettween mixer and PGA can achieve channel selection and image rejection of the signal after down-conversion with active Gm-C structure. The center frequency of the filter is 2MHz and the bandwith of the fiter is the same with the channel. A class AB PA is choosed for the transmmiter.The project is accomplished with Spectre or SpectreRF and Virtuoso in cadence platform in GSMC 0.18 um process. Some module requires the Matlab such as complex filter. The simulations show that the RX is achieved with NF of 6.3dB and gain of 25 dB to 100 dB while the TX is achieved with the maximum output power of 10 dBm and the other specifications can meet the design requirements very well.