Design of a new squaring function for the Viterbi algorithm

An approximate squaring method has been developed for the Viterbi algorithm that is faster and more area efficient than conventional exact squaring methods and table look-up. Using Monte-Carlo simulations, it is shown here that the performance of the Viterbi algorithm is not degraded using this approximation. The circuit performance is verified by implementing a 7-b approximate squaring function in a 2-/spl mu/m CMOS process. It operates at a maximum speed of 20 MHz, consumes 95 pW/Hz of power, and occupies an active area of 380 /spl mu/m/spl times/650 /spl mu/m. >