| 摘要 |
A Viterbi decoder including an Add-Select-Compare unit with a new butterfly unit (300) having only two adders (310, 320), compared with a conventional butterfly unit's four adders, for processing a trellis transition having branch metric of zero. The new butterfly unit (300) is thus of reduced complexity (saving 8% of the total Viterbi decoder complexity in a typical example). Methods are also disclosed for producing suitable metrics for use with the new butterfly unit, and for optimizing these metrics by dynamic scaling (particularly suitable for OFDM applications) and adaptation for additive noise. The invention is particularly suitable for high speed, low-power implementations for broadband communications applications, and may be implemented in software or hardware.
|
