Patent ID: 7567622

Claim:
An ARQ re-transmission method in a wireless communication system wherein data packets are transmitted from a transmitter to a receiver using a higher order modulation scheme wherein more than two data bits are mapped onto one data symbol to perform a first transmission and at least a second transmission based on a repeat request, the method comprising: modulating data packets at the transmitter using a first mapping of said higher order modulation scheme to obtain first data symbols; performing the first transmission by transmitting the first data symbols over a first diversity branch to the receiver; receiving at the transmitter the repeat request issued by the receiver to retransmit the data packets in case the data packets of the first transmission have not been successfully decoded; modulating, in response to the received repeat request, said data packets at the transmitter using a second mapping of said higher order modulation scheme to obtain second data symbols; performing, in response to the received repeat request, the second transmission by transmitting the second data symbols over a second diversity branch to the receiver; demodulating the received first and second data symbols at the receiver using the first and second mappings respectively; and diversity combining the demodulated data received over the first and second diversity branches, wherein: the first and second mapping of said higher order modulation schemes are pre-stored in a memory table.