Baseband Demodulation Unit in Code Division Multiple Access System Receiver with P.N.Despreader Minimizing Quantization Error

摘要

The technical field to which the invention described in the claims belongs.;A baseband demodulation device for a code division multiple access system receiver.;B. Technical problem to be solved;Provided is a baseband demodulation device having a PN despreader that reduces quantization error in demodulation of a signal received at a code division multiple access system receiver.;C. Summary of the Solution;The present invention provides a baseband demodulator for a code division multiple access system receiver, comprising: a PN code generator for generating and outputting an I-channel PN code and a Q-channel PN code; and an I-channel PN code and a Q-channel PN applied from the PN code generator. When the combination of logic levels of the code is in the first state, the received I channel signal is subtracted from the I channel signal received from the IF terminal, and the received I channel signal is added to the received Q channel signal to despread the first I, Generate a Q channel signal; When the combination of the logic levels is in the second state, the received I channel signal is added to the received I channel signal, and the received Q channel signal is subtracted from the received I channel signal to despread the second I and Q channel signals. Generate; When the combination of the logic levels is in the third state, generating the third I and Q channel signals having a complement of 1 to the first I and Q channel signals; A complex PN code despreader for generating and outputting a fourth I and Q channel signal having a complement of 1 to the second I and Q channel signals when the combination of the logic levels is in a fourth state, and outputting from the complex PN despreader A pilot signal demodulation section that demodulates a pilot signal from the despread I-channel signal and the Q-channel signal, and demodulates I-channel symbols and Q-channel symbols from the despread I-channel signals and Q-channel signals output from the complex PN despreader; Characterized by including a symbol demodulation unit.;D. Significant Uses of the Invention;Used for code division multiple access system receiver.