Cvsd ( continuous variable slope delta modulation ) voice coding enables operation at high bit - error rates 連續可變斜率增量調制的語音編碼可以在高誤碼率的情況下正常工作。
Our object is an intermediate frequency modem of a software defined radio transmitter - receiver of multi - service , multi - modulationmode and multi - processdatarate . first , related software defined radio theory is introduced ; later , channels of transmitter - receiver are designed with consideration of data format , modulation , fec , interwaving . and scrambling ; emphasis is placed on theory and implementation of an audio compression algorithm cvsd ( continuous variable slope delta modulation ) and a fec technique convolutional coding - decoding 本文首先介紹了相關的軟件無線電理論;然后完成了包括數據格式,調制方式,糾錯碼方式,交織器和擾碼器等部分的中頻調制解調器通道設計;接著著重介紹了系統中使用的音頻壓縮算法cvsd (連續可變斜率增量調制)的原理和實現,以及作為前向糾錯碼的卷積碼編碼理論和編解碼的高效實現。