The Simulation Design And Implementation Based On Rayleigh Fading Hannel Rate Adaptation Algorithm

In the process of wireless signal transmission in Rayleigh fading channels,the transmission medium is very unstable conditions will be subject to attenuation,delay distortion,noise and other aspects of the impact,resulting the change of an instantaneous signal to noise ratio in wireless channel.In order to achieve the optimization of wireless network resources utilization,rate adaptive technology emerged,and can select the best available rate adaptive transmission rate varies with time according to channel conditions.The core rate adaptive algorithm is how to choose the best rate for data transmission based on channel real-time changes.A lot of domestic and foreign scholars of this area have done a lot and achieved good results.However,the existing rate adaptation algorithm only considers the free space loss while ignoring the actual presence of Rayleigh fading.Change will have significant impact on the decline of the algorithm the actual channel environment.It works on the actual guide,algorithm performance research fading channel environment with good practical significance.In this paper,CHARM,RAM,RADM rate adaptation throughput and bit error rate performance in Rayleigh fading channels statistical algorithms,and analyzes of poor arithmetic error rate performance reasons,these three rate adaptation algorithms proposed to improve M-Charm,ERAM,M-RADM algorithms to quickly adapt to changes in Rayleigh fading channel,can select the appropriate transmission rate,while taking into account both the BER performance,but also take into account the throughput performance,simulation The results showed that:1.M-charm,E-RAM algorithm reduces the error rate and access to a larger throughput,packet loss rate is low,and most channel conditions deteriorate performance of less than 3dB.2.Based on the rate of loss rate statistics adaptive algorithm RADM algorithm change better slow fading channel tracking performance,throughput and bit error rate performance are good,low loss rate;when the channel fading fast changes,the original Short-term and long-term rate adjustment mechanism algorithm has been improved to enhance the sensitivity and adaptability of the algorithm,compared to the original algorithm,M-RADM in ensuring certain requirements under the BER improved throughput.Finally,the algorithm is implemented on the hardwear platfom,and rate adaptive scattering communication modem is developed.After verificated outside,we can find that adaptive rate scatter communication system can automatically choose the optimal communication rate according to the channel condition,thus makes the channel to maximize the use of.To verify the validity of the rate adaptation algorithm.