Study on adaptive data rate scheme on a mobile channel

移动数据业务对传输数据速率的要求越来越高。扩大无线电频段在法律上是不容易允许的。多值调制降低了通信质量，在用户信道数量减少的情况下仍采用多码方案，本文研究了基于时间和信道的自适应数据速率方案，该方案以W-CDMA方案为基础。该系统采用软件无线电(SDR)技术设计，实现了数据速率的自适应控制。数据速率为、128Kbit/S、256Kbit/S和1.024 Mbit/S，无线带宽为5 MHz，频率为2 GHz。通过计算机仿真和用现场可编程门阵列(FPGA)和PC机组成的硬件样机设计，从实践上证实了系统具有足够的特性和易于控制的特点。

Enhancement of transmission data rate is rapid in demand on mobile data service. Expanding of radio band is not easily permitted in law. Multi-value modulation degrades the quality of communication, and multi-code scheme is used in spite of reduction of number of user channels.In this study, adaptive data rate scheme is studied time and channel dependent valuation of data rate and contents by users.The W-CDMA Scheme is taken as the basis of this scheme. The system is assumed to be design by Software Defined Radio (SDR) technology for adaptive control data rate. The data rates of 64, 128, 256, 512 kbit/s and 1.024 Mbit/s are taken for 5MHz radio bandwidth at 2GHz. Sufficient characteristic with easy control was confirmed practically with computer simulation and prototype hardware designed with are Field Program Gate Array (FPGA) with a MPU and PC.