Central Problem of Channel Coding Theory for Past 50 Years
Encoding is Easy: Most codes are good provided they are
long enough. Average PE over all
Decoding is Hard: Exponentially increasingly with length, N.
Decoder Complexity ~ 2K = 2RN
Some Partial Facilitators:
Algebraic Block Codes: Ease decoding, but suited primarily to hard decisions and do not nearly approach capacity.
Convolutional Codes: Performance-complexity tradeoff improved.
Concatenated Codes: “Divide and Conquer” Separate encoding and decoding into two or more levels.