CORDIC-Augmented Sandbridge Processor for Channel Equalization

Abstract

In this paper we analyze an architectural extension for a Sandbridge processor which encompasses a CORDIC functional unit and the associated instructions. Specifically, the first instruction is CFG CORDIC that configure the CORDIC unit in one of the rotation and vectoring modes for circular, linear, and hyperbolic coordinate systems. The second instruction is RUN CORDIC that launches CORDIC operations into execution. As case study, we consider channel estimation and correction of the Orthogonal Frequency Division Multiplexing (OFDM) demodulation. In particular, we propose a scheme to implement OFDM channel correction within the extended instruction set. Preliminary results indicate a performance improvement over the base instruction set architecture of more than 80% for doing channel correction, which translates to an improvement of 50% for the entire channel estimation and correction task.

CERA: A Channel Estimation Reconfigurable Architecture

“…In [2], a reconfigurable MPSoC architecture is developed to manage the whole OFDM baseband system, including the channel estimation functionality. An extension of the Sandbridge processor with a CORDIC unit is studied in [3], and the channel estimation algorithm implemented combines two different methods (LS-LI and LS-TDI) thus performing interpolation in both frequency and time domains.…”