Research And Realization Of TOFDM Modem Technology

This case's goal is to realize reliable transmission of information in strong multi-path channel. The TOFDM modem technology presented in the paper has the following prominent characteristics, such as strong anti-multi-path interference, excellent frequency offset resist and low peak-to-average power ratio (PAPR), that provides a feasible solution for wireless communication between multi-path objects.The correlated concepts and problems of TOFDM modem from basic concept to actual circuit design are explained completely. First of all, the case requirements, the primary concepts of multi-carrier modulation and TOFDM modulation are introduced in this paper. Secondly, common phase modulation technology is explained and theπ/4-DQPSK modem technology which is adopted in this project is expounded completely. Next, the kernel techniques of TOFDM are introduced as emphasis, in which the reason and solution of symbol interference are analyzed. Correlated concepts of PAPR and the function of PAPR in communication system are explained, at the same time, simulation for PAPR of TOFDM is processed using Matlab. According to the analysis, the design and calculation method for the multiplexing number of TOFDM signal and signal bandwidth are presented, and then, bit synchronization method for variable parameter channel is put forward and analyzed. Based on the above analysis, combining the requirements of the project, the TOFDM modem circuit design and software and hardware implementation are achieved, whose devices selection principle and the basic characteristics are analyzed in detail. The anti-white noise performance in constant parameter channel is tested, and also the anti-multi-path interference and anti-white noise performance at stimulant multi-path condition are measured indoor. At last, the summarization and expectation are presented.Finally, this article has completed the TOFDM modem's fundamental research and has realized the software and hardware design. The test results indicate that the moderm has the strong fight against multi-path capabilities to meet the system requirements。...