FSO-WOFDM系统的实验研究

在无线光正交频分复用（FSO-OFDM）系统中，因需要加入循环前缀而消耗近20%的带宽，降低了数据传输效率。为了进一步减少带宽损耗，改善系统性能，采用小波包变换代替FSO-OFDM中的傅里叶变换，设计了一种基于小波变换的无线光正交频分复用（FSO-WOFDM）系统。该系统无需加入循环前缀，利用小波基函数的正交性来抑制子载波间的干扰。根据FSO-WOFDM系统原理，研究了信道估计方法、湍流强度、小波基对FSO-WOFDM系统误码率的影响，对比分析了FSO-WOFDM与FSO-OFDM的系统性能，并通过实验验证了FSO-WOFDM系统的可行性及其优良的抗混合噪声干扰能力。

Experimental study on FSO-WOFDM system

In the free space optical orthogonal frequency division multiplexing (FSO-OFDM) system, nearly 20% of the bandwidth is consumed due to add a cyclic prefix, the data transmission efficiency is reduced. In order to further reduce the bandwidth loss and improve the system performance, a wavelet packet transform was used instead of the Fourier transform in FSO-OFDM, free space optical orthogonal frequency division multiplexing system based on wavelet transform (FSO-WOFDM) was designed. The system didn't need to add a cyclic prefix, and the orthogonality of the wavelet basis functions was used to suppress inter-carrier interference. According to the principle of FSO-WOFDM system, the effects of channel estimation method, turbulence intensity and wavelet based on the bit error rate of FSO-WOFDM system were studied. The system performance of FSO-WOFDM and FSO-OFDM was compared and analyzed. The experiment verifies the feasibility of FSO-WOFDM system and its excellent ability to resist mixed noise.