基于训练序列进行系统优化的60GHz正交频分复用-光载无线通信系统

Optimization of 60 GHz Orthogonal Frequency Division Multiplexing Radio-over-Fiber System Based on Training Sequence

分析了60 GHz正交频分复用-光载无线通信(OFDM-RoF)系统中OFDM信号经光纤传输后在光电检测时存在的子载波间互拍干扰(SSBI)现象。提出使用交叉型训练序列结构的OFDM信号来降低SSBI的影响。实验证明,在无色散补偿的情况下,2.5 Gb/s交叉型训练序列结构的基带OFDM信号在58 GHz毫米波系统中经光纤传输20 km后,在误码率为10-3时,其功率代价仅为0.5 dB,而连续型训练序列结构OFDM的功率代价为2 dB。说明基于交叉型训练序列结构的OFDM信号的传输性能在抵抗SSBI方面要明显优于连续型训练序列结构OFDM信号。

There is signal-signal beating interference （SSBI） when the orthogonal frequency division multiplexing （OFDM） signal is detected by PIN after transmiting over the fiber in 60 GHz OFDM radio-over-fiber （RoF） system. The interleaved configuration of training sequence of OFDM signal is proposed to decrease the influence of the SSBI. The experimental results show that after the 2.5 Gb/s interleaved OFDM signal transmitting over 20 km single mode fiber in 58 GHz millimeter-wave system, the power penalty of the interleaved OFDM signal is only 0.5 dB at the bit error rate （BER） of 10-3 without dispersion compensation. In comparison, the power penalty of the continued OFDM signal under the same conditions is 2 dB. It is demonstrated that the fiber transmission performance of the interleaved OFDM signal is better than the continued OFDM signal in robust tolerance against SSBI.