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微波通信灵活方便,光纤通信码速率高,无线激光通信兼具微波和光纤通信的优势,但受大气环境的影响不容忽视,差错控制是克服无线激光通信环境影响的一个有效方法。常见的纠错码有RS码、Turbo码和Ldpc码,分别将RS(15,9)码、RS(30,10)码,码长为128码率为1/2的LDPC码、交织长度为64码率为1/3的Turbo码引入无线激光通信系统中,按照设计的实验方案,进行一年多时间的实际测量,对几种前向纠错码的性能进行了比较,实验结果表明:RS(30,10)码纠错能力最强,Turbo码纠错性能稍逊于RS(30,10)码。RS(15,9)码与码长为128,码率1/2的LDPC码的纠错性能相差不大。在不同的雨天环境中,通过采用前向纠错码,可以将误码率从10-4降低到10-6以下;在雪天,可以将误码率从10-3降低到10-5以下;在大雾条件下,可以将误码率从10-3降低到10-5以下;在一般晴好天气下,可以使误码率降低到10-9以下。
Microwave communication is flexible and convenient. The rate of optical fiber communication codes is high. Wireless laser communication combines the advantages of microwave and optical fiber communication. However, it can not be ignored due to the influence of atmospheric environment. Error control is an effective way to overcome the influence of wireless laser communication environment. Common error correction code RS code, Turbo code and Ldpc code, RS (15,9) code, RS (30,10) code, the code length of 128 code rate of 1/2 LDPC code, interleave length of 64 turbo codes with code rate of 1/3 are introduced into the wireless laser communication system. According to the designed experimental scheme, the actual measurement of more than a year is carried out. The performance of several kinds of forward error correction codes are compared. The experimental results show that: The RS (30,10) code has the strongest error correction capability and the Turbo code error correction performance slightly less than the RS (30,10) code. The error correction performance of the RS (15,9) code and the code length of 128 and code rate 1/2 are not different. In different rainy days, the bit error rate can be reduced from 10-4 to below 10-6 by using a forward error correction code; in the snow, the bit error rate can be reduced from 10-3 to below 10-5 ; Under the condition of heavy fog, the bit error rate can be reduced from 10-3 to below 10-5; under normal sunny weather, the bit error rate can be reduced below 10-9.