OFDM系统相对于单载波系统来说,同步技术尤为关键.由于OFDM系统各个子载波间的正交性,使得OFDM系统对频率偏移非常敏感,为了保证系统性能的良好,我们要保证频率的稳定性.本文分析了同步误差对OFDM系统性能的影响,给出了一种新算法,仿真表明OFDM系统频率同步误差比时间同步误差对系统性能的影响要严重得多,只有当OFDM系统频偏小于0.02个子载波间隔时,系统才是处于稳定性能的,这时它所产生的ICI对系统的影响可以忽略不计.%Compared with the single-carrier system, OFDM system synchronization is particularly critical. As the orthogonality between any two sub-carriers in OFDM system, the OFDM system is very sensitive to frequency offset. The frequency offset will cause serious inter-subcarrier interference (ICI) so that to degrade the system performance. This paper analyzes the synchronization error in the OFDM system, and presents a new algorithm. Simulations show that the OFDM system frequency synchronization error is more serious impact to system performance than time synchronization error. Only when the frequency synchronization error is less than 0.02 OFDM system sub-carrier interval, the ICI resulting is less impact to system performance, and can be negligible.
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