For a given channel estimation variance

a new metric for Turbo decoding on Ricean channel was proposed

and a novel formula for channel reliability factor Lc was concluded. The presented simulation results show that Turbo decoding with the proposed metric can obtain 0.1~0.6dB more code gain than that with the conventional metric. Furthermore

the performance with the modified metric excels under the condition of significant fading factor and small channel estimation variance

and approaches to the performance on the AWGN channel.