ASIC implementation of physical downlink shared channel for LTE

摘要

Long Term Evolution (LTE) is a paradigm for mobile communication providing high speed data. The LTE terms provide a framework for enlarged capacity, enhanced spectrum efficiency and coverage as well as condensed latency as compared to the second and third generation wireless networks. Six downlink channels are used by LTE of which three are data bearing channels and the rest are control channels. Physical Downlink Shared Channel (PDSCH) is the key among the data channels. The paper discusses the AS IC realization of PDSCH transmitter architecture consisting of addition of Cyclic Redundancy Check bits, channel coding, rate matching, scrambling, modulation, precoding and mapping to resource element as well as the receiver architecture comprising of resource element demapping, Multiple Input Multiple Output receiver processing, demodulation, descrambling, rate de-matching and channel decoding. The channel coding used is turbo coding and the turbo coding is realized using Maximum a-posteriori probability algorithm. The modulation schemes used are QPSK, 16-QAM and 64 QAM. The transmitter and receiver architectures are implemented for the aforesaid modulation schemes and the differences are compared. The tools used for implementation purpose are Xilinx IS E 14.2 and ISim both of which are provided by Xilinx and for synthesis and layout, tools provided by Cadence such as RTL compiler and Encounter were used.