Research On Key Technologies Of Physical Downlink Shared Channel In LTE System

This thesis designs an implementation for Physical Downlink SharedChannel (PDSCH), which will be studied profoundly in later chapters, in LTESystem.Firstly, the thesis brings a brief idea of the key technologies for PDSCHin LTE System, such as Multiple Access Scheme, OFDM technology, Framestructure, Parameter setup and Prossess of the Physical Layer. Generally, theOFDM technology cuts the bandwidth into subcarriers, each of which isOrthogonal to other and has the ability to transmit signals separately orintegrately. But, OFDMA, as a sub technology of OFDM, which supports anaccess method more flexible, most significantly, divides the availablebandwidth into tiny parts and shares them between multi-users.Secondly, this thesis introduces how dataflow proceeds in PDSCH.PDSCH is the primitive data channel in LTE System downlink channel, everyuserdata travels on it but System Broadcast Information and PagingInformation. Data processing procedure includes MAC and higher Layer’s courses will be analyised in the second chapter.Thirdly, this thesis emphasizes the schemes and key technologies relateto the Physical Layer of PDSCH. Particularly, Cyclic RedundencyCheck(CRC), Code Block Segmentation, Turbo encoding and Rate Matchingconsists the bit level algorithms of PDSCH, and the symbol level algorithmcontains Modulation, Layer Mapping and Precoding, etc.Ultimately, the thesis shows the scheme of implementation of PDSCHbased on the FPGA technology, meantime, it is the core and hinge spot in thisarticle. This final chapter analysises the bit level algorithms of PDSCH mainly,which improves the original pattern-serial data processing into advancedpattern we called parallel streamline data processing. Much time will be saved,structure will be optimized and Data Sequence between other downlinkchannel shall be aligned more smoothly, if take a try on this parallelstreamline data processing method. The only and irreplaceable reason tochoose this proposal is to offer more time easing the pressure for Schedulingalgorithm in Media Access Control Layer.