Research Of Prediction Method For TD-SCDMA Base Stations Electromagnetic Radiation

With the rapid development of the mobile communication industry,people are pay attention to the effects of electromagnetic radiation from base stations.For time-division multiple access communication system such as TD-SCDMA,researchers introduced the maximum duty cycle to predict the average electromagnetic radiation based on the maximum electromagnetic radiation.But actual duty cycle of signal is often lower than the maximum duty cycle,which leads to the predictive results higher than the real electromagnetic radiation.In order to solve the above problems,this paper analyzes the channel allocation mode of TD-SCDMA system and calculates the actual duty cycle of downlink transmission signal according to the channel allocation strategy.Then accurately predicts the average electromagnetic radiation of TD-SCDMA base stations through actual duty cycle.The main contents and innovations of this paper are as follows:(1)For TD-SCDMA base stations electromagnetic radiation under channel segmentation strategy,a method for predicting electromagnetic radiation of TD-SCDMA base stations based on channel segmentation is presented in this paper.The method establishes the service queuing model according to the channel segmentation strategy of TD-SCDMA system and calculates the actual average duty ratio of the TD-SCDMA signal in the station by the service queuing model.Then predicts the average electromagnetic radiation of TD-SCDMA base stations through the actual average duty cycle and the maximum electromagnetic radiation of the signal.In order to ensure the accuracy of the prediction results,this paper analyzes the parameters of the spectrum analyzer.The prediction results are very close to the actual average radiation which deviation rate is only 2.9%,and the prediction efficiency is greatly improved since measurement time from the original 30 minutes to 1 minute.(2)For TD-SCDMA base stations electromagnetic radiation under channel shared strategy,a method for predicting electromagnetic radiation of TD-SCDMA base stations based on channel shared is presented in this paper.The method establishes the Markov model according to the channel shared strategy of TD-SCDMA system,and the actual duty cycle of the signal is calculated by using the Markov model.Then accurately predict the average electromagnetic radiation of the TD-SCDMA basestations.For TD-SCDMA base stations under channel shared mode,the deviation rate of prediction results are 3.4%.