This brief presents an energy-efficient soft-input soft-output (SISO) decoder based on border metric encoding, which is especially suitable for nonbinary circular turbo codes. In the proposed method, the size of the branch memory is reduced to half and the dummy calculation is removed at the cost of a small-sized memory that holds encoded border metrics. Due to the infrequent accesses to the border memory and its small size, the energy consumed for SISO decoding is reduced by 26.2%. Based on the proposed SISO decoder and the dedicated hardware interleaver, a double-binary tail-biting turbo decoder is designed for the WiMAX standard using a 0.18-μm CMOS process, which can support 24.26 Mbps at 200 MHz.
|Number of pages||5|
|Journal||IEEE Transactions on Circuits and Systems II: Express Briefs|
|State||Published - 2008|
Bibliographical noteFunding Information:
Manuscript received October 27, 2006; revised February 14, 2007 and June 18, 2007. This work was supported by the Institute of Information Technology Assessment through the ITRC and by IC Design Education Center (IDEC). This paper was recommended by Associate Editor M. Maggio.
- Low power design
- Maximum a posteriori (MAP) algorithm
- Nonbinary turbo codes
- Turbo decoding