Research On Lte-A Coordinate Multi-Point Transmission And Reception Joint Process

With the rapdly development of mobile internet,3GPP have initiated the standardization of LTE-Advanced after release the first version of LTE, to cope with the challenge of Wimax, Coordinated Multi-Point Transmission and reception was involved in LTE-Advanced to improve the cell average and cell edge spectrum efficiency. CoMP was classified into Joint Process and Coordinate Schedule. This thesis foucs on Joint Process, Multiple basestations in the cooperative set transmit the data to UE simultaneously at the cost of the share of data and control information among basestations to reduce the inter cell interference, consequently the users spectrum efficiency in the cell edge was improved.Couple of issues need to be solved before CoMP was implemented.,such as how to design a fine precoding matrix to cancel the multi-user interference;how to made tradeoff between feedback overhead and system performance. These two issues were addressed in this thesis.Fistly, when it comes to the Joint Process Precoding, the performance of BD and SLNR in both perfect CSI and limited feedback was firstly detailed. And two improved algorithms with respected to SLNR were researched, which both started from SLNR. CISVD was based on maximize sum rate and another one was based on receiver precoding matrix nesting iteration.Secondly, in limited feedback case, some enhanced feedback schemes named adaptive feedback and differential feedback were researched, the impact of different type of convariance matrix was evaluated. Adaptive and differential feedback both outperformed raditional feedback scheme. According to the3GPP contribution, an appropriate feedback scheme was researched. Simulation results demonstrated that3bits to quantized inter-CSI-RS information performed well in feedback overhead and system performance improvement tradeoff. Then a new adaptive feedback scheme was proposed for CoMP JP and won performance improvement.Finally a new adaptive feedback allocate scheme was proposed, the feedback bits were classified into two parts. Some of the bits are occupied by CoMP users, which were adaptively allocated for different cells according to the channel quality. And the rest of the feedback bits were used by single cell MU-MIMO users for two stage adaptive feedback. And simulation results demonstrated the proposed scheme perform well in cell edge and gain multi-user diversity.