FPGA-based Inner Receiver Design and Implementation for WiMAX

• Main Authors: Po-Chi Chen, 陳伯奇
• Other Authors: Tai-Lang Jong
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/53443186429357335359

碩士 === 國立清華大學 === 電機工程學系 === 94 === In wireless communication system, air is the medium of signal propagation. There are many channel effects in signal propagation that distort transmitted signal, such as multi-path, fading, Doppler effect, path-loss, shadowing, AWGN, and so on. Except channel effects, the hardware circuit itself has some effects in distorting the transmitted signal such as carrier frequency offset, sampling frequency drift, etc. We can recover the transmitted signal from the received distorted signal precisely with some estimation and compensation, which is developed by digital signal processing in base-band, at the receiver. In the synchronization process, the receiver performs packet detection in time domain to judge whether the signal is received or not. Then the receiver precedes the estimation of frequency offset and OFDM symbol boundary. After FFT operations, the receiver estimates and compensates for the channel effect in frequency domain, and tracks the carrier phase. These works described above are completed by the inner receiver. After these operations, the non-ideal channel effects are reduced substantially. Moreover, the original information can be reconstructed by error correcting code, such as Reed Solomon and Viterbi. In this thesis, our goal is to design and implement the inner receiver for signal synchronization. First, we investigate theoretically the algorithms for inner receiver. Then, we simulate the algorithms for synchronization, analyze the performance and adjust the algorithms by using MATLAB. Finally, we implement these algorithms by hardware circuit, verify the design and evaluate the synchronization performance with FPGA. The experimental results verify that our design of inner receiver actually achieves the WiMAX specification in function and speed.