SDR and wireless infrastructure

hanges in the economy over the last two years have profoundly affected engineering efforts at the leading manufacturers of telecommunications equipment. Declines in revenue and profit have been followed by reductions in R&D spending. This is particularly true in the area of wireless infrastructure, one of the most promising applications for SDR technology. However, we can remain optimistic, with the center of gravity moving more to the startups, which are more aggressive in bringing the technology to market. Keeping in mind the sensitivity of intellectual property in the new developments, we are very pleased to present some representative articles in this issue. The first article, “A Total Cost of Ownership Approach to Evaluating Different Reconfigurable Architectures for Baseband Processing in Wireless Receivers” by Rupert Baines and Doug Pulley, outlincs a total cost of ownership approach that can be used to evaluate different SDR approaches to development of UMTS base stations. Once reconfigurable equipment is deployed in the field, systems tuning, functional changes, and standards migration (which otherwise’require expensive hardware modifications) can be accommodated purely in software. Software has its own challenges, hut reduced dependence on hardware reduces touch labor and thus many of the recurring costs of standards migration. This scalability, cost effectiveness, and ease of development are vital for the successful rollout of 3G semices around the world. David Chester and John McCardleYs article focuses on “Self Timed Logic in Software Radio Applications.” The classical SDR bottleneck, high speed and wide dynamic range data conversion, can be overcome with the selective application of a class of asynchronous logic referred to as delay-insensitive logic. Finally, the third article, “A Software Defined Baseband Communications Design” by John Glossner et al., focuses on underlying technologies to implement a full software-based platform, including a multithread processor architecture and its silicon realization, as well as a software development environment. Looking into the next several years, a few important trends should be observed. During the past year, Moore’s Law gave us high-volume production of million-gate field programmable gate arrays (FPGAs) from multiple sources with high-quality software tools. This bodes well for FPGA roles in SDR, and for low-power and modal processing hardware configurations for a wide range of processor-controlled devices and systems from video survcillance to automobiles and refrigerators. System on a chip (SoC) architectures may soon he deployed with large reconfigurable co-processors hosted by industry-standard instruction set architectures (ISAs) like the Intel Pentium, Motorola embedded microcontroller, Power PC, or ARM. All this bodes well for the future of software and DSP in radio as the three articles in this installment of Software and DSP in Radio clearly illustrate. Best wishes in the New Year, Joe Mitoln and Zornn Zvonar