The Design And Implementation Of Bit Error Rate Measuring Software For Digital Mobile Radio Terminals Which Work In Direct Mode

When work in direct mode, the communication performance of DMR terminals isoften affected by various noises or interferences.To ensure the bit error rate performanceof DMR terminals, to measure the Bit Error Rate in the process of the communication isvery necessary. Therefore, To develop a bit error rate measure software appropriated forDMR terminals which work in direct mode, the following problems are needed to besolved.Firstly, research how to generate test sequence for every signalings created byDMR terminals during the process of communication in direct mode. Built efficient biterror rate test model.Secondly, simulate the AWGN Channel, adjust SNR and power of the signal to betransmit to the receiver of DMR terminals, design the sequence synchronization andBER estimate algorithm.Ultimately finish the developmenting. a bit error rate measure software used tomeasure the bit error rate performance of DMR terminals which work in direct mode,my main work of this paper as follows:Firstly, put forward the software requirement of the BER measure software.putforward testing scenarios and test model by studying Ptotocol stack, signaling and thecommunication mechanism of DMR, then offer software functional requirements andperformance requirements.Secondly, design the software architecture and interface definition. Based on therequirement of the BER measure software. Divide the software into three layers: userinterface layer, function controlling layer and signal processing layer, describe thefunctions of every layer and Dividing cell, and define the software interface.Thirdly, realize the fuctions of every layer. Especially signal processing layerwhich includes calculating test time and the length of the test sequence, producing andsending the test sequence, realizing AWGN channel and adjusting signal power,synchronization and calculating BER.At last, finishthe functional and performance test, and test results show that it canwork correctly and has met the requirement of users. The test results are following:(a) Calculating unit of test time and the length of the test sequence can workcorrectly under the conditions of different signaling and different confidence.(b) Signal source unit can generate and send the sequences precisely right.(c) Channel simulation unit produces AWGN sequence whose probabilitydensity function has a average error with normal probability density functionis lower than0.002. (d) BER measure results: for speech signals, BER measure precision attain103and106for the other signaling.Above all, the bit error rate measure software offerred by this article for DMRterminals which work in direct mode which meets the users’ requirements.and the testmethod is effective.which generates AWGN sequence based on look-up table is a highefficiency method which improves the speed of arithmetic speed.