一种克服脉位脉宽信号码间干扰的均衡算法  

Block Decision Feedback Equalization of PPM+PWM Modulated Signals

作　　者：田骅[1] 樊养余[1] 原勐捷[1] 谭庆贵 

机构地区：[1]西北工业大学信号处理与无线光通信研究所,陕西西安710072 [2]西安空间无线电研究所,陕西西安710001

出　　处：《计算机仿真》2009年第9期321-324,共4页Computer Simulation

基　　金：重点实验室基金(9140C5301010701);陕西省自然基金(2007F10)

摘　　要：使用脉位脉宽调制的室内红外无线通信系统,信号光经过红外信道会产生严重的码间干扰,因此需要在接收端使用均衡器进行处理。常用的迫零反馈均衡算法性能不够理想,针对脉位脉宽调制信号提出了一种MMSE分组判决反馈均衡算法。以最小均方误差原理为基础,同时简化了均衡器中判决器的结构,并使用信号抽取技术设计反馈系数,能够一次反馈多个符号以提高补偿效果。仿真实验表明,与经典的迫零均衡算法相比,算法在误比特率为时抗噪声性能提高了近3dB,并且能够适应更加复杂的信道条件,具有广阔的应用前景。In the indoor infrared wireless communication system using PPM ＋ PWM modulation, signal light would have serious intersymbol interference （ISI） through infrared wireless channel. Therefore, the equalizer in the receiver is needed. The performance of commonly used zero forcing algorithm is not idel, so a new MMSE block decision feedback equalizing algorithm for PPM ＋ PWM signals is proposed. This algorithm is based on MMSE theory and simplifies the structure of the decision device of equalizer. It also uses Signal decimation method to improve the design of feedback coefficients, which means that the equalizer can efficiently feedback more than one symbol at the same time. Compared with traditional zero forcing algorithm, simulating result shows that this new algorithm can improve the performance by 3dB at BER . Therefore, the proposed block decision feedback equalizing algorithm can obviously reduce the ISI and is adapted to more complicated channels, which could promise a broad application prospect.

关 键 词：室内红外无线通信 脉位脉宽调制 分组判决反馈均衡 最小均方误差 脉位脉宽信号判决器 信号抽取 

分 类 号：TN911.7[电子电信—通信与信息系统]