Question

Which parameter is used in soft decision algorithm?

(a) Euclidean distance

(b) Euclidean distance squared

(c) Euclidean distance & distance squared

(d) None of the mentioned

I got this question in semester exam.

This interesting question is from Properties of Convolution Codes and Reed-Solomon Codes in portion Channel Coding of Digital Communications

Answer 1

The correct choice is (c) Euclidean distance & distance squared

For explanation: As soft decision decoding algorithm has limited resolution it cannot use hamming distance metric. Instead it uses Euclidean and monotonic metric such as Euclidean distance squared.