Claims: 1. A method for generating soft decision bits for Quadrature Phase Shift Keying (QPSK) signal in a wireless communication receiver (100), the method comprising: receiving and storing a plurality of in-phase and quadrature-phase (I-Q) samples in an I data buffer (204a) and a Q data buffer (204b) respectively; calculating absolute values for a block of I samples and a block of Q samples by a first absolute value calculation unit (206a) and a second absolute value calculation unit (206b) respectively; determining boundaries of the absolute values of the I and Q samples by a first boundary estimation unit (208a) and a second boundary estimation unit (208b) respectively; determining a plurality of levels within the boundaries of the absolute values of the I and Q samples based on step sizes by a first level calculation unit (210a) and a second level calculation unit (210b) respectively; and generating a plurality of soft bits for each I sample based on the determined levels for the I sample by a first soft value decision unit (211a) and a plurality of soft bits for each Q sample based on the determined levels for the Q sample by a second soft value decision unit (211b); wherein the plurality of soft bits for the I sample include a Most Significant Bit (MSB) indicative of a sign of the I sample and all other Bits (LSBs) indicative of the strength of the I sample, and wherein the plurality of soft bits for the Q sample include a MSB indicative of a sign of the Q sample and all other bits indicative of the strength of the Q sample. 2. The method as claimed in claim 1, wherein calculating boundary of the I-Q samples comprises: determining, by the first boundary estimation unit (208a), a maximum value of the output of the first absolute value calculation unit and a minimum value of the output of the first absolute value calculation unit; and determining, by the second boundary estimation unit (208b), a maximum value of the output of the second absolute value calculation unit and a minimum value of the output of the second absolute value calculation unit. 3. The method as claimed in claim 2, wherein determining a level within the boundaries of the absolute values includes calculating, by the first level calculation unit (210a), the step size as: step size=I_delta/2(N-1) for uniform spread step size