Study Of RF Transceiver Front-end Applied To Broadband Wireless Communications System

In recent years,broadband short-distance wireless communications technology become a hot research field of global communications technology,the concept of wireless local area network(WLAN) and wireless personal area network(WPAN) raise the climax of research in short-distance wireless communications.As higher data rates,shared with other wireless communication frequency resources,realization simply,low power ,can through walls and so on,broadband wireless communication can widely applicated in wireless multimedia local area networks,wireless sensor networks,intelligent transportation systems and military system.As people demand higher and higher performance and stability of wireless communication,RF block became a research focus,such as personal communication and base station,wireless access system,satellite communications,GPS,WLAN,etc.In wireless communications,RF block directly influence the performance of communication system,Broadband Wireless Communication make demands on RF front-end about small size,light height,low voltage,loe power,and make higher demands on template spectrum of transmitted signals,efficiency of transmitter,the receiver sensitivity and dynamic range.This article is designed a RF front-end with high receiver sensitivity and high transmitter wireless broadband RF spectrum template,grate value to improved the performance of communication,and has been applied to broadband wireless communication.First,this paper general introduced the broadband wireless communications technology and its research statusquo,on the basis of summarized relebant literature,analysis the RF technique requirements of broadband wireless communication.Secondly,this paper compared and ayalysis several commonly used RF transceiver architecture,then explained and analyzed leading indicator of RF transceiver.Designed a wireless broadband RF transceiver subsystem using two frequency conversion of super-heterodyne architecture,work in TDD mode,it can achieved all performance of RF transceiver,meet the SC-FDE and OFDM signal requiments.In design process,analysis mainly factors of influence transceiver performance:transceiver architecture,IF frequency planning,receiver sensitivity, anti-interference performance, intermodulation and dynamic range.The sixth chapter gives test results of RF transceiver system,these showed that:when the bandwidth is 8MHz,the gain of transmitter is 30dB,the range of ALC is greater than 30dB,ACPR is better than -40dBc;the receiver sensitivity can reach -96dBm under QPSK1/2 modulation,the maxiam of gain is 68dB,the range of AGC is greater than 100dB. The seventh chapter summarized this paper.