Design of software radio for cellular communication systems and wireless LANs

Software radio base and personal station prototypes for cellular communication systems are designed and implemented. The prototypes are composed of commercial multipurpose DSPs and CPU, pre- and post-processors, A/D/A converters, and RF/IF units. In order to use processor resources effectively, the DSP program handles signal processing in physical and data-link protocol-layers, while the CPU program takes charge of high protocol-layers including call control and system control. The prototypes support various air interfaces, some of which are equivalent to the 384 kbit/s transmission rate PHS (personal handy phone system) and a 96 kbit/s transmission rate FDMA/TDD system. Excellent transmitting and receiving performance, compared to conventional hardware radios, is achieved. In addition, expanding the prototypes to support IEEE 802.11 wireless LANs is examined. This paper describes the design and evaluation of the prototypes for cellular systems, and discusses issues and strategies for supporting IEEE 802.11 wireless LANs.