Comparative study of joint-detection based on FFTs and the 2-RAKE receiver of the TD-SCDMA up-link [2-RAKE read 2D RAKE]

JD (joint-detection) and 2D RAKE (two-dimensional RAKE) receiver method are two important methods of MUD (multiuser detection) of the TD-SCDMA (time division synchronization-code division multiple access) up-link. We compare these two method for complexity and performance. In the JD method, we also use FFTs (fast Fourier transforms) and overlapping to reduce the computational complexity. We analyze the complexity and performance of these two methods theoretically and also apply Monte Carlo simulation to them. From the analysis and the simulation, we can draw the conclusion that the performance of JD based on FFTs is better than that of the 2D RAKE in the TD-SCDMA up-link, but with more complexity. The analysis and simulation do not involve intercell interference and the simulation channel is the Rayleigh channel based on 3GPP TS 25.105.