SIMPLIFIED DEMODULATION METHOD USING SOFT DECISION METHOD INCLUDING SIMPLE CALCULATION PROCESS

摘要

PURPOSE: A simplified demodulation method using a soft decision method including a simple calculation process is provided to reduce complexity of modulation and improve efficiency of a receiver by performing once only an addition process or only a subtraction process. CONSTITUTION: A transmission signal of a QPSK modulation method is received. A symbol constellation of the received signal is produced. A phase shift process for the produced symbol constellation is performed. Soft output values of I and Q elements are produced from the phase shifted symbol function. A final soft output value is obtained by compensating the amplitude corresponding to the phase shift of the soft output values.