Burst-by-burst adaptive joint-detection CDMA/H.26L based wireless video telephony using TTCM and LDPC codes

A low bit-rate video coding techniques using the H.26L standard codec for robust transmission in mobile multimedia environments are presented. For the sake of achieving error resilience, the source codec has to make provisions for error detection, resynchronization and error concealment. Thus a packetization technique invoking adaptive bit-rate control was used in conjunction with the various modulation scheme employed. In this contribution, we propose a burst-by-burst adaptive coded modulation-aided joint detection-based CDMA (ACM-JD-CDMA) scheme for wireless video telephony and characterise its performance when communicating over the UTRA wideband vehicular fading channels. The coded modulation schemes invoked in our fixed modulation mode based systems are low density parity check code based block coded modulation (LDPC-BCM) and turbo trellis coded modulation (TTCM). The performance of LDPC-BCM was evaluated and compared to that of TTCM in the context of the ACM-JD-CDMA system using a practical modem mode switching regime. Both schemes exhibited a similar transmission integrity, although the LDPC arrangement is capable of achieving this at a lower complexity.