Design and implementations of a software defined radio scheme based modem for high-speed multimedia data service

In-recent years, there is much attention on software defined radio(SDR) schemes for high speed multimedia. applications in near future. It is required that the. SDR system is flexible enough to support multiple air interfaces and signal processing functions at the same time. And also, digital signal processors and FP.GAs are widely used for implementation of these adaptive, and flexible functions of a baseband modem for SDR applications. Meanwhile, it is known that the modulation schemes of OCQPSK. (Orthogonal Complex QPSK) and HPSK (Hybrid PSK) are used for IMT-2000 services of synchronous systems and asynchronous systems, respectively. Thus, we, design and implement an OCQPSK/HPSK modem using a DSP chip with consideration of SDR concepts. One modulation, scheme is operated by adaptive selection between the two schemes and 5 physical traffic channels differentiated by orthogonal bodes are implemented in one DSP chip and each channel has 1 Mbps data rates and 8 Mcps chip rates.