Patent ID: 9124319
Filing Date: 2015-09-01
Classification: H04B,H04J,H04L,H04W

Abstract:
1. A method implemented in a user equipment used in a multi-user multiple input multiple output (MU-MIMO) wireless communications system, the method comprising: receiving from a base station an indication of a first modulation type for the user equipment; receiving a first data signal and a first precoded pilot for the user equipment; receiving a second data signal and a second precoded pilot for a co-scheduled user equipment, where a second modulation type for the co-scheduled user equipment is unknown to the user equipment; comparing with a threshold a norm of a channel estimate determined from the second precoded pilot for the co-scheduled user equipment; if the norm exceeds the threshold, deciding the second modulation type through modulation classification algorithm exploiting an assumption that the second modulation type remains constant within a resource block; processing the first data signal and the second data signal by using the first modulation type and the second modulation type to perform interference cancellation; and generating a log-likelihood ratio (LLR) for the user equipment, wherein each of the first modulation type and the second modulation type is any one of 4-QAM (quadrature amplitude modulation), 16-QAM, or 64-QAM, and wherein the modulation classification algorithm is responsive to probabilities assigned to the three choices for the second modulation type.