A WiMAX turbo decoder with tailbiting BIP architecture

A tailbiting block-interleaved pipelining (TB-BIP) is proposed for deeply-pipelined turbo decoders. Conventional sliding window block-interleaved pipelining (SW-BIP) turbo decoders suffer from many warm-up calculations when the number of pipeline stages is increased. However, by using TB-BIP, more than 50% of the warm-up calculations are reduced as compared to SW-BIP. We have implemented a TB-BIP WiMAX turbo decoder with four pipeline stages in the area of 3.8 mm
²
using a 0.18 µm CMOS technology. The chip achieved 45 Mbps/iter and 3.11 nJ/b/iter at 99 MHz operation.