Patent ID: 8494077

Claim:
A method for transmitting data in a communication system, the communication system comprising: a first base station (BS 1 ) comprising a first transmitter (Tx 1 ), a second base station (BS 2 ) comprising a second transmitter (Tx 2 ), the first transmitter (Tx 1 ) and the second transmitter (Tx 2 ) sharing a frequency band, a first user equipment (UE 1 ) comprising a first receiver (Rx 1 ), a second user equipment (UE 2 ) comprising a second receiver (Rx 2 ), a first channel (C 1 ) being provided between the first transmitter (Tx 1 ) and the first receiver (Rx 1 ), a second channel (C 2 ) being provided between the second transmitter (Tx 2 ) and the second receiver (Rx 2 ), a first cross-channel (Cx 1 ) being provided between the second transmitter (Tx 2 ) to the first receiver (Rx 1 ), and a second cross-channel (Cx 2 ) being provided between the first transmitter (Tx 1 ) and the second receiver (Rx 2 ), the method comprising the steps of; a) selecting the first channel (C 1 ) and the second channel (C 2 ) wherein the first cross-channel (Cx 1 ) has low power and the second cross-channel (Cx 2 ) has high power, b) receiving by the second receiver (Rx 2 ) first data being intended to be sent from the first transmitter (Tx 1 ) to the first receiver (Rx 1 ) and frequency resource information of the first transmitter (Rx 1 ), c) performing a non-linear pre-coding for second data (D 2 ) being intended to be sent from the second transmitter (Tx 2 ) to the second receiver (Rx 2 ) based on second channel coefficients of the second channel (C 2 ), and d) sending the pre-coded second data (D 2 ) from the second transmitter (Tx 2 ) to the second receiver (Rx 2 ), sending a first non-pre-coded data (D 1 ) from the first transmitter (Tx 1 ) to the first receiver (Rx 1 ) at the same timeframe, and sending a message from the second base station (BS 2 ) to the second user equipment (UE 2 ) for informing the second user equipment (UE 2 ) to measure channel coefficients and to report the channel coefficients, wherein the second receiver (Rx 2 ) measures second cross-channel coefficients of the second cross-channel (Cx 2 ) and the second channel coefficients of the second channel (C 2 ) and identifies significant second channel coefficients, the significant second channel coefficients comprising coefficients having large values.