Turbo Unequal Error Protection Codes with Multiple Protection Levels

Most existing Turbo unequal error protection (UEP) codes provide two error protection levels at the cost of extending the block size of the codeword or increasing the computational complexity. This paper proposes two novel Turbo UEP coding schemes, which provide multiple error protection levels for information bits, according to their different sensitivities to the channel noise. By permuting the information bits and designing the puncturing scheme, multiple error protection levels can be achieved using one encoder without increasing the computational complexity. In addition, the coding rate of the proposed Turbo UEP schemes can be chosen from 1/3 to 1/2. Experimental results show that the information bits with a high protection level resist noise more effectively than those with a low protection level. The proposed UEP schemes provide better capability of error protection for the entire information, compared with the Turbo equal error protection (EEP) schemes and the existing Turbo UEP schemes.