Wireless packet transmission with variable processing gain control in packet-switched and circuit-switched mode integrated DS-CDMA systems

A DS-CDMA system with both a circuit-switching scheme for voice transmissio n and a packet-switching scheme for data transmission is effective in multi media communication required to transmit a variety of media. Although the S lotted-ALOHA system is believed to be an effective packet-switched system f rom the perspectives of transmission efficiency and interference power, onl y open loop transmit power control is used because of the difficulty in usi ng closed loop transmit power control in the ALOHA system. In this paper, w e analyze the performance of open loop transmit power control that uses a p ower margin to obtain the quality required even in packet-switched terminal s, and propose wireless packet transmission with variable processing gain c ontrol as the method to achieve high-speed transmission by more effectively using the free channels. The results of computer simulations showed that t he system capacity of circuit-switched terminals is not damaged when an app ropriate power margin is set, and the additional effect of the packet-switc hed terminals is increased. In addition, the proposed system can greatly sh orten the average delay time of packet-switched terminals. (C) 2001 Scripta Technica.