Research On The Physical Layer Simulation And Channel Estimation Algorithms Of DSRC

Dedicated short range communication(DSRC)is one kind of communication technology for short distance(tens of meters to one kilometer)wireless transmission.It is mainly used for VTV(vehicle to vehicle)and VTR(vehicle to roadside infrastructures)communications.Different from traditional wireless environments,transmitter and receiver of VTV communication are both in fast-moving.DSRC system working under a significant time-varying channel.In addition,the vehicles moving in a changing scenario which resulting in a poor wireless propagation environment.On the other hand,DSRC physical layer is inherited from WLAN protocol IEEE 802.11a which works in indoor low-speed environment.Both of them use the training sequences in the preamble to estimate the frequency response of the channel,and compensate all transmission data symbols during entire frame time which brings low bit error rate(BER)and packet error rate(PER)performance in high mobility and time-varying environment.In order to improve the performance of DSRC physical layer,this paper studies the working process of DSRC physical layer and constructs the channel model in different scenarios of VTV communications.Based on the research and simulation of serval classical DSRC channel estimation algorithms,this paper proposes two novel DSRC channel estimation algorithms:TFVDA algorithm and MRC-Based algorithm.TFVDA algorithm uses the output of Viterbi decoder to reconstruct data pilots.On the one hand,it uses the time-domain correlation properties of channel to decide the result of channel estimation.On the other hand,it uses the frequency-domain correlation properties of channel to interpolate and gets the complete channel frequency response.TFVDA algorithm can track the channel accurately in the high-order modulation condition.MRC-Based algorithm uses the result of channel estimation in the frequency domain to provide phase compensation for maximal ratio combining and brings diversity gain.So the MRC-Based algorithm can provide reliable wireless transmission capability under high speed and high-order modulation scenarios for vehicle multimedia applications.