Constant envelope encoder and decoder with error correction for wideband CDMA communication system

摘要

PURPOSE: A fixed amplitude encoder and decoder including an error correction function in a wideband CDMA(Code Division Multiple Access) communication method is provided to include the error correction function by maintaining transmission amplitude as fixed amplitude. CONSTITUTION: A root cosine roll-off filter(405) filters a received signal to a band signal including a fixed bandwidth. A multiplier(410) converts the filtered signal into a baseband signal for a local oscillator. An LPF(Low Pass Filter)(415) filters the converted signal into the baseband signal. Another multiplier(420) multiplies a PN(Pseudo Noise) transmitted from a transmission apparatus to an LPF signal. A four-by-four decoder(400) corrects errors of a signal received from the multiplier. A PS(Parallel to Serial) conversion unit(460) converts parallel data outputted from the four-by-four decoder to serial data.