Patent ID: 9136988
Filing Date: 2015-09-15
Classification: H04L

Abstract:
1. A method of transmitting data, by a transmitter, using hybrid automatic repeat request (HARM), the method comprising: transmitting initial data to a receiver, the initial data being mapped on a signal constellation, wherein the initial data is scrambled by a scrambling code; receiving a non-acknowledgement (NACK) signal for the initial data from the receiver, the NACK signal indicating that the receiver did not receive the initial data successfully; generating retransmission data by shifting the phase of the initial data on the signal constellation, the phase of the initial data being shifted by performing bit masking on the initial data based on a bit masking pattern, wherein the phase of the initial data is shifted by π radians using a bit masking pattern (−1,−1) in a QPSK signal constellation, a bit masking pattern (−1,−1,+1,+1) in a 16 QAM signal constellation, and a bit masking pattern (−1,−1,+1,+1,+1,+1) in a 64 QAM signal constellation, wherein the bit masking pattern is used for mitigating inter-cell interference and inter-symbol interference, wherein a diversity gain is obtained by changing a channel selectivity based on the phase shift performed using the bit masking pattern, and wherein a residual inter symbol interference (ISI) operating to each of a first user equipment and a second user equipment located in the same cell is canceled by the phase shift performed using the bit masking pattern; and transmitting the retransmission data to the receiver.