Flexibility and Reusability in the Digital Front-End of Cognitive Radio Terminals

Abstract

From the issue entitled "Special Issue on Embedded Signal Processing Circuits and Systems for Cognitive Radio-Based Wireless Communication Devices"International audienceEmerging communication paradigms like the cognitive radio require extremely flexible physical layer functional units that can be parameterized at runtime for supporting multiple modes. Parameterizing the hardware accelerators in the cognitive radio baseband incurs a latency penalty, which is a function of the amount of reconfiguration data required by the accelerators. In an opportunistic spectrum access scenario, the cumulative latency required to reconfigure all the physical layer units when switching to a new channel, reduces the useful time available for transmission leading to a lower system throughput. Against this background, this paper gives an overview of the amount of reconfiguration data required by different candidate accelerator architectures for performing the computationally intensive channelization function, in the digital front-end of the cognitive radio terminal. The paper also identifies opportunities for reusing hardwired stages of a channelization accelerator across multiple modes, while minimizing the reconfiguration overhead

Cognitive radio equipments supporting spectrum agility

“…Reuse at the level of coarse grained datapath-operators significantly reduces the reconfiguration overhead. In our earlier works [10][11], we have investigated the flexibility and reuability issues in the channelization function of the digital front-end, which incorporates the signal processing tasks of channel selection, interferer attenuation, pulse shaping and sample rate conversion. It was shown that identifying redundancies across multiple channelization specifications at an early stage in the design cycle could be used for designing channelization accelerators in which a significant portion can be hardwired and reused across multiple standards with minimal overheads for reconfiguration.…”