CODE-RATE INCREASED COMPRESSED MODE DS-CDMA SYSTEMS AND METHODS

摘要

PURPOSE: A CDMA communication technique in cellular radio telephone communication systems is provided which is related to handover of connections between frequencies using intermittent Direct Sequence-Code Division Multiple Access(DS-CDMA) transmissions. CONSTITUTION: An introduction of discontinuous transmission in CDMA communications techniques is achieved by using selectively punctured coded output of a convolutional encoder. By temporarily increasing the coding rate during a frame, the coded information only fills an information part of a frame in a compressed mode, leaving an idle part of the frame in which to perform other functions, such as evaluation of other frequencies for use in handover between frequencies. A mode control device can switch an encoded signal stream output from a convolutional encoder between a first signal processing branch associated with a normal mode of transmission and a second signal processing branch associated with a compressed mode of transmission, the latter of which includes a code puncturing unit.