Turbo product codes and their bandwidth efficiency

Communication systems designers have always dealt with tradeoffs between performance, cost, and the efficient use of the available spectrum. Proliferation of wireless systems makes the issue of bandwidth efficiency a paramount consideration. Turbo codes, and in particular, the turbo product codes (TPCs) presented in this paper provide an excellent means of improving bandwidth efficiency. Of course, once it is established that turbo provide improved bandwidth efficiency, the next questions are, cost and bit error rate (BER) performance level. This paper presents a tutorial overview of TPCs with examples for using TPCs to achieve improved bandwidth efficiency. TPCs excel at high code rates and are readily coupled with high order modulation. The result, as is shown, is that TPCs can provide dramatic improvements in bandwidth efficiency and with a relatively low implementation cost.