对光码分多址接入系统中由于各个用户距离和发射功率不同导致的远近效应进行研究。结果表明 ,远近效应显著劣化了小功率用户的误码率和掉线率。而且 ,系统中用户的信号功率方差越大 ,各个用户的误码率和掉线率的劣化也越严重。提出了一种应用光硬限幅器消除远近效应的方法 ,该方法还极大地降低了多用户干扰 In the optical code division multiple access system due to each user distance and transmit power caused by the different distance effect. The results show that the near-far effect significantly degrades the bit error rate and dropped rate of low power users. Moreover, the greater the signal power variance of users in the system, the worse the bit error rate and drop rate of each user are. A method of using optical hardware limiter to eliminate the near-far effect is proposed. The method also greatly reduces the multi-user interference