4 QPSK modulator and modulating method using FIR filter for multiple input bits and 4 channels

摘要

The present invention includes four 1-bit 1 input from a single filter structure: relates to a QPSK modulator that implements the four interpolation FIR filter operation the eggs FIR filter two 4-channel multi-bit input epeuahyi for using the filter processing at the same time.; Such a 4-channel multi-bit input epeuahyi quadrature phase shift keying modulated using the Al filter apparatus, the pseudonoise spreading means for branching a 1-bit data inputted from the four-channel PN spread by generating an eight bit data; the FIR filtering means for receiving the eight 1-bit data, perform filtering for pulse shaping, and the multiplier means to output the data of n-bit multiplied by the respective channel-specific gain to the filtered output from the FIR filtering means; the n-bit data output from the multiplication means quadrature phase shift keying modulation and characterized by including adding means for outputting an I channel signal and Q channel signal.