Two multi-rate transmission schemes, multi-code (MC) and variable-spreading-length
(VSL) code, for realizing multimedia communications on three types of OFDM-CDMA
systems are proposed. These systems can be integrated into a programmable structure
such that the operation can be controlled and adjusted by system parameters and
thus the transceiver can be used in different systems without changing the fundamental
hardware and software architecture, which serves the trend of software-radio for
future application. A transceiver architecture of multi-rate OFDM-CDMA systems
is illustrated and showed its programmability such that the general system can
operate under different scenarios with a common hardware structure and reconfigure
by software implementation.