Abstract: A receiver system of a wireless communication system comprising means for receiving and decoding of punctured convolutional codes and characterized by comprising a soft-decision processing unit adapted to receive a number of quantized signal soft-decision values spread across a range, the range having a maximum value, a minimum value, and a value corresponding to the center of that range; shift a number of signal soft-decision values by a shift step away from said center value; and quantize the signal soft-decision values with fewer bits than the number used to quantize the received signal soft-decision values according to a determined quantization input-output relationship.