Application Research Of LDPC In UWB System

Since UWB technology has a lot of advantages such as high date rate, low power spectral density, high precision location identification and inherently exceptional multipath immunity, it has become the research focus in the wireless communication field. However, performance is limited by the low signal-to-noise (SNR) and high date rate. A potential solution is to add a strong error correcting code. So studying the error correcting code on UWB system is necessary and worthy.In the thesis, I first summarize the characteristics and development of UWB technique and point out the necessary of channel code in UWB system based on the characteristics of UWB signal, and then introduce why LDPC code is fit for the UWB system. The focus of this thesis is on the structures of LDPC codes and the decoding algorithm. The thesis proposes a LDPC coding-decoding scheme based the bitfilling algorithm. The LDPC code's parity check matrix generated by this scheme has high girth and can be used to coding directly, the coding complexity is lower. As to the decoding algorithm, I modify the Message Passing algorithm based on the girth that I can get in the structure of parity check matrix to improve the decoding performance. What is more, the new structure of the parity check matrix is easy to implement with the hardware. Finally, I simulate the performance of LDPC codes with different parameters on the UWB system. We find that the performance of LDPC codes is very good. We believe LDPC codes will become the main channel-coding scheme in the future UWB system.