Test Enabled Process Tuning for Adaptive Baseband OFDM Processor

Fine Grain Precision Scaling for Datapath Approximations in Digital Signal Processing Systems

“…There are two drawbacks in their work: the authors use the same word length across the whole design and their method requires dedicated training symbols to find the best word lengths at run time in a self-adjusting scheme, which introduces additional overhead that negates some of the power savings. In [3], the authors use both precision and voltage scaling to maximize power reduction. They first optimize word lengths according to the channel environment and then use these word lengths to find the optimal voltage that still satisfies a required error rate.…”

“…Traditionally, fixed-point word lengths of custom hardware or software implementations are set to match worst-case operating conditions determined at design time. In more aggressive recent power saving methods, a system's precision is dynamically and adaptively configured in reaction to changing operating points while maintaining a certain signal quality level [7,3,9,10]. Such dynamic precision scaling mostly targets application-specific hardware implementations [7,3,10], although software implementations also exist [9].…”

“…Given the large number of variables and operating points to optimize for, traditional simulation-based approaches are too time-consuming. This is a main reason why fine-grain precision scaling is not widely employed, where designers and programmers instead resort to conservative worst-case analysis, self-adjusting runtime schemes [7,3], which come with additional overhead, or coarse-grain approaches that assume the same precision or a limited number of precision levels across the whole design, which leaves additional power saving opportunities through fine-tuning of each variable's word length unexploited.…”

Optimal power reduction on wireless OFDM receiver

“…Therefore, the digital circuit will develop using that cell library. In terms of time constrain for design, we do not require trial-and-error as in [7]. Our application is the lowpass filter of an OFDM receiver.…”

“…A method for tuning the wordlength of digital baseband OFDM signal processing algorithms has been developed based on gated clocks [6], and minimum power locus [7]. The gated clock requires clock management in system.…”