Research On Precoding And FPGA Implementation In TD-LTE-A System

As a candidate for4G, LTE-A(Long Term Evolution-Advanced, LTE enhanced version)using multiple antenna enhancement technology as the core technology of the physical layer.Due to system performance can be improved exponentially through extended space’stransmission dimension, so MIMO(Multiple Input Multiple Output) enhanced technology hasattracted much attention, and also becomes a hot issue of the LTE-Aprotocol standardization.The transmission mode9of LTE downlinkmulti-antenna system supports downward maximum8antennas configuration. At the same time, enhanced space division multiplexing wasconsidered to be one of the key technologies of LTE-A.And LTE-Awas a system which usingcodebook feedback channel state information, so it is necessary to research the codebook ofbased-limitedfeedback.First, the article introduces the basic principle of multi-antenna technology, and expoundstheprecoding in LTE and LTE-Asystem,mainlyincludingtransmit diversity,space multiplexingand beamforming. On the basis of this,8antennas space multiplexing was mainly focused, andseveral8-antennas double codebook was given, including Qualcomm plan, Ericsson plan,Samsung plan and the8-antennas double codebook in R10. Then, a new8-antenna doublecodebook design approach was proposed for TD-LTE-Advancedsystems. Compared with the8-antenna double codebook in Rel-10protocol, they had the same feedback overhead, but thenew one had greater distance between codewords. Simulation results show that under the samesimulationcondition, compared withthe traditional8-antenna doublecodebook, the new one canmakethe systemhave lower bit errorrateandhigher averagesystem capacity.Finally,according to codebook design plan, finish the FPGA hardware implementation ofprecoding.Includingthe overall design concept of precoding module,device selection and so on.The simulation results show that this method can finish precoding well in meeting the delayindexof LTE system.