Turbo code at 0.03 dB from capacity limit

We propose a rate 1/3 infinite-length irregular turbo code capable of achieving an error rate P/sub eb/=10/sup -5/ at signal-to-noise ratio E/sub b//N/sub 0/=-0.46 dB, which is at distance 0.03 dB from Shannon capacity limit. Our turbo code is derived by a simple modification of the original Berrou-Glavieux code.