Burst-by-burst adaptive coded modulation-aided joint detection-based CDMA for wireless video telephony

Abstract

http://www-mobile.ec.soton.ac.uk A bstract-A Burst-by-Burst Adaptive Coded Modulation-Aided Joint Detection-Based CDMA (ACM-JD-CDMA) scheme is proposed for wireless video telephony and characterise its performance when communicating over the UTRA wideband vehicular fading channels. The coded modulation schemes invoked in our Axed modulation mode based systems are Trellis Coded Modulation (TCM), Turbo TCM (TTCM), Bit-Interleaved Coded Modulation (BICM) and Iterative-Decoding assisted BICM (BICM-ID). When comparing the four schemes at a given complexity, TTCM was found t o be the best scheme and the performance of the TTCM-assisted ACM-JD-CDMA system was evaluated using a practical modem mode switching regime.

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

“…For the sake of further benchmarking, our results recorded for a similar TTCM ACM/CDMA system using the H.263 codec [5] are also depicted in Figure 6. These results show that under the same channel conditions and using the same system parameters, the H.26L codec The video quality versus PLR performance can be more explicitly observed in Figure 7.…”

“…Furthermore, the number of slots per frame is 15, and the frame duration is 10ms. For the sake of benchmarking, the remaining system parameters were the same as in [5].…”

“…Turbo TCM (TTCM) is another bandwidth efficient scheme that has a structure similar to that of the family of power-efficient binary turbo codes [3], but employs TCM schemes as component codes [2,4]. It has been shown in [5] that TTCM is capable of outperforming other coded modulation schemes in the context of H.263 based video telephony [6], when communicating over the UMTS Terrestrial Radio Access (UTRA) wideband vehicular fading channel [7,8], while maintaining a comparable decoding complexity.…”