A study on high speed data transmission in DS-CDMA and adaptive modulation based TDMA dual mode scheme for wireless multimedia communication systems

摘要

This paper proposes a DS-CDMA and adaptive modulation based TDMA dual mode scheme to realize both high speed data and high quality voice transmission in the multimedia communication environment. In the TDMA sub-frame adaptive modulation scheme is employed, in which modulation level is adaptively controlled according to the received CIR so as to increase the maximum bit rate for high rate data services. Moreover, transmit power control and dynamic channel assignment are also employed to sufficiently use spectral resource in the TDMA sub-frame. Computer simulation confirms that the proposed scheme can greatly reduce the average delay time for data transmission without decreasing quality of voice media.