A Characterisation of HSDPA Capacity Using EXIT Chart Techniques

High-Speed Downlink Packet Access (HSDPA) is currently in use as 3.5G operating at various transmission rates with a peak rate of 14.4MMBit/s. Turbo code with higher order modulation is used in channel coding and modulation. In this paper the extrinsic information transfer chart (EXIT chart) analysis has been applied as a tool to evaluate the performance of High Speed Downlink Packet Access (HSDPA) with turbo encoding. It has been shown that the UMTS turbo code is not fully utilizing the capacity of the channel as the throughput is less than the attainable capacity of the channel. The performance evaluation is based on analysis for QPSK modulation and code rate 1/2 and 1/3 respectively.