OCQPSK modulator and modulating method using 1-bit input FIR filter

摘要

A modulator for an IMT-2000 synchronous mobile station in a digital telecommunication and modulating method thereof, and more particularly, an OCQPSK modulator using FIR filters, each for performing 1:4 interpolation operations for 4 input data and a modulating method thereof. The orthogonal complex quadrature phase shift keying OCQPSK modulating apparatus uses a 1-bit input FIR filter that includes pseudo noise spreading for bifurcating 1-bit data inputted from input channels and pseudo-spreading the bifurcated 1-bit data, an FIR filter for receiving the 1-bit data and performing a filtering operation for pulse shaping, a gain multiplying block for multiplying filtered data outputted from the FIR filter by a gain for respective channels, and a channel adder block for adding data outputted from the gain multiplying block to output I channel and Q channel signals.