Patent ID: 9729298
Date: 2017-08-08
CPC Classifications: H04J,H04L,H04W

Claim:
1. A method of configuring a positive acknowledgement (ACK) or negative acknowledgement (NACK) in a wireless communication system based on time division duplex (TDD) in which M, M=4, downlink subframes are associated with an uplink subframe, the method performed by a user equipment receiving a physical downlink shared channel (PDSCH) and a physical downlink control channel (PDCCH) and comprising: receiving, by the user equipment, at least one downlink transport block in the M downlink subframes from a first serving cell; determining, by the user equipment, ACK/NACK states {HARQ-ACK(1), HARQ-ACK(2), HARQ-ACK(3), HARQ-ACK(4)} for the first serving cell; and determining, by the user equipment, an ACK/NACK response based on the ACK/NACK states, wherein the PDCCH carries a downlink grant including a downlink assignment index (DAI) which indicates an accumulative number of PDCCHs with assigned PDSCH transmission, wherein the ACK/NACK states {HARQ-ACK(1), HARQ-ACK(2), HARQ-ACK(3), HARQ-ACK(4)} are determined among possible ACK/NACK states, the possible ACK/NACK states comprising at least six states of (A, A, A, N/D), (A, A, N/D, any), (A, D, D, D), (A, A, A, A), (N/D, any, any, any) and (A, N/D, any, any) except for (A, D, D, D), where ‘A’ indicates an ACK, ‘N’ indicates a NACK, ‘D’ indicates discontinuous transmission (DTX), and ‘any’ indicates any of ACK, NACK and DTX, wherein the ACK/NACK states {(A, D, D, D), (A, A, A, A)} are mapped to a first state associated with ACK/NACK resources, the ACK/NACK states {(N/D, any, any, any) and (A, N/D, any, any) except for (A, D, D, D)} are mapped to a second state associated with ACK/NACK resources, and the first state is different from the second state, and wherein HARQ-ACK(j), j=1, 2, 3, 4, is ACK/NACK/DTX for a corresponding downlink transport block on the PDSCH with a DAI value j in a corresponding PDCCH.