Minimum mean squared error approach to interference cancellation and maximum likelihood decoding of space-time block codes

摘要

Block-encoded transmissions of a multi-antenna terminal unit are effectively detected in the presence of co-channel interfering transmissions when the base station has a plurality of antennas, and interference cancellation is combined with maximum likelihood decoding. More specifically, the signals received at the base station antennas are combined in a linear combination that relates to the channel coefficients between the various transmitting terminal units and the base antennas. By selecting proper coefficients for the linear combination and choosing probable transmitted signals that minimize a minimum mean squared error function, the signals of the various terminal units are canceled when detecting the signal of a particular unit. In another embodiment of the invention, the basic approach is used to obtain an initial estimate of the signals transmitted by one terminal unit, and the contribution of those signals is removed from the received signals prior to detecting the signals of other terminal units.

主权项

1. A method comprising:
generating estimates of channel characteristics of channels between a receiver that uses M receiver antennas and K synchronized terminal units that each transmit on N antennas, the receiver including a processor and a memory configured to store at least one corresponding sequence of instructions executable on the processor; and estimating symbols that were transmitted by a corresponding terminal unit of the K synchronized terminal units, the estimating being based on the estimates of channel characteristics, the symbols being estimated by suppressing signals from all but the corresponding terminal unit, where K, M, and N, are integers, 2≦K≦M, and N>1, wherein the generating and the estimating include executing at least one sequence of instructions on the processor, and wherein the symbols are estimated based on maximum likelihood decoding and one of zero forcing interference cancellation and minimum mean-squared error interference cancellation.