Energy efficient turbo decoding for 3G mobile

The requirement of turbo decoding in 3G wireless standards has forced handset designers to consider power consumption issues in their implementations. The phenomenal performance of turbo codes comes at the expense of computation. Primarily this paper looks at methods of substantially reducing the power consumption for the decoding operation, making it feasible to integrate turbo decoders into a low power handset. The techniques presented include early termination of the turbo process, encoding of extrinsic information to reduce the memory size, and disabling portions of the MAP algorithm when the results will not affect the decoded output. The net result of these techniques is almost a 70% reduction in power over a fixed 6 iteration, 8-state baseline turbo decoder at 2 dB of signal to noise ratio (SNR).