低成本光载多带正交频分复用超宽带信号的产生和传输研究

The multi-band orthogonal frequency division multiplexing ultra-wideband singal over radio-over-fiber system is raising great interest since they allow for high data throughput with low power consumption which is very applicable to the digital home requirements. However, there are some problems such as complex, high cost and low transmission performance exist in current related research. And the theory of multi-band orthogonal frequency division multiplexing ultra-wideband singal over radio-over-fiber system and the study on the fiber transmission performance have not been reported. In the project, we propose and experiment a cost-effective method of optical multi-band orthogonal frequency division multiplexing ultra-wideband signal generation. In order to investigate the transmission performance of ultra-wideband signal over radio-over-fiber system, we develop mathematical models for optical and wireless components such as laser diode, external modulator, single mode fiber, air interface. Using these models, we evaluate the transmission performance of ultra-wideband signals over single mode fiber and wireless transmission. Meanwhile channel coding and channel estimation algorithm are proposed to improve the transmission performance of multi-band orthogonal frequency division multiplexing ultra-wideband signal over radio-over-fiber system. In a word, these innovation works in the project can be done to improve the integration of ultra-wideband wireless signals and optical transmission technology, and promote the development of broadband wireless communications network in theoretical and practical.

光载多带正交频分复用超宽带是提供未来吉比特速率无线信号宽带接入极有潜力的方案。可是，目前的相关研究存在系统实现复杂、成本高、传输性能需要提高等问题。基于本项目组已实现60GHz正交频分复用的光纤无线通信系统实验，本项目拟在此基础上探索低成本的光学产生多带正交频分复用超宽带信号的方法，首次将多带正交频分复用超宽带信号在光纤和无线信道中的传输看成一个整体，建立统一的数学模型，系统研究其传输特性并进行优化；提出一种新的信道编码和信道估计算法降低光纤信道的非线性失真和光纤色散对多带正交频分复用超宽带信号的影响；最后通过实验验证提出的方法和算法的性能。本项目所取得的创新性成果对实现超宽带信号与光纤接入技术的融合，促进我国无线宽带接入网的发展具有理论和实际价值。

在国家基金的支持下，围绕多带正交频分复用超宽带信号的产生与传输，以及适于光纤信道传输的信号处理技术等一系列问题，我们按照申请书的计划开展研究工作，并取得了预期的研究成果，这些成果都通过实验验证，包括：多带正交频分复用超宽带信号的光学产生方法；建立多带正交频分复用超宽带信号的光纤无线传输的系统模型，降低多带正交频分复用超宽带信号的光纤色散影响，提高传输性能；利用低密度奇偶校验码有效提高系统的接收灵敏度；在接收端进行符号内频域均衡和导频辅助信道估计方法相结合，以及基于多带正交频分复用超宽带信号搭建直接检测光纤无线通信系统进行实验研究。本项目组发表SCI收录的论文 15篇，EI收录的论文1篇，EI收录的会议论文4篇，申请了国家发明专利3项，已授权1项。