正交频分复用系统的自适应调制技术优化在无线网络中的应用

摘要

In view of the multimode optical fiber high frequency area deep decline point for orthogonal frequency division multiplexing (CO-OFDM system performance and the effect of using the distribution of the optical signal to noise ratio threshold algorithm of adaptive modulation technology was improved, through the experimental results of the algorithm and the modulation process, it is concluded that: the design of the algorithm effectively realizes the adaptive modulation to choose, when the channel characteristic is better to use higher-order modulation transmission more information, when the channel characteristic is poorer lower modulation order preach not even less information, reduce the system ber. Comparative experiments show that under the condition of the same bit error rate, compared with the system without the use of adaptive modulation technique to improve system light about 2 db lower signal-to-noise ratio; To improve the system transmission performance better, achieve more simple. The algorithm is applied to the fire alarm system, it is concluded that: multimode optical fiber transmission can effectively detect the general positioning of the energy loss and loss, can achieve accurate transmission of the fire. The study of practical significance for structural engineering safety.%针对多模光纤高频区深衰落点对正交频分复用系统性能的影响，采用光信噪比门限的分配算法的自适应调制技术进行改进，通过算法与调制过程的实验结果，得出：设计的算法有效地实现了自适应调制选择，在信道特性较好时使用高阶调制多传信息，在出现的信道特性较差时降低调制阶数少传甚至不传信息，减少了系统误码率。对比实验表明：在相同误码率条件下，与不使用自适应调制技术的系统相比改进系统光信噪比要低2 dB左右；改进系统传输性能更好，实现更为简单。将算法系统应用到火灾报警当中，得出：多模光纤传输能够有效的检测能量损失及损耗点的大体位置，能够准确实现火情的传输。这一研究对于我国无线网络的发展有一定的实际意义。