Study On TD-LTE Base Station Cooperative Processing

TD-LTE, namely TD-SCDMA long term evolution, is a competitivemobile communication technology of satisfying user equipment (UE) demandsin the future; meanwhile, as the only member of3GPP LTE TDD standard, itis the key of3G development and evolution in our country. Base station (BS)cooperation is one of the competitive techniques to reduce inter-cellinterference, and improve the spectrum efficiency. To be specific, it mainlyfocuses on two kinds of technology: coordinated scheduling and jointprocessing. Joint processing constitutes a virtual MIMO structure with UEsthrough the cooperative communication, and then realizes multi-cellcooperative transmission and reception to mitigate the inter-cell interference,and improve the spectrum efficiency and coverage of the residential edge UEs.It is this paper’s research. Studing BS cooperative processing in the TD-LTEmechanism is the main content of this paper.This paper first shows channels’ spread characteristic, establishing thechannel model in the BS cooperative system; it then studies variouscooperation modes, mainly divided into two kinds: BBU+RRU basedcooperation modes and conventional BS cooperation modes; this paper alsointroduces the CSI obtaining method of BSs, and analyses and comparisesvarious joint linear pre-coding technology basing on the BS cooperativesystem model.This paper proposes an average BER minimization based joint linearpre-coding technology and a SLNR maximization based joint linearpre-coding technology, which are demonstrated to maintain better BERperformance and perform more robustness to the imperfect CSI than classicalalgorithms; it designs a broadband adaptive modulation technology, whichrealizes bit loading and power distribution according to the different channelgains, providing six kinds of MQAM modulation; this paper also presentsantenna selection based spatial diversity mechanism and spatial multiplexing mechanism, which improve the spectrum efficiency of two-waycommunication in the BS cooperative system and transmission reliabilityeffectively.