New tight bound on the bit error probability for turbo codes

Abstract

A good method of evaluating the performance for turbo codes is the theoretical upper bounds on the bit error probability for turbo codes with uniform interleaver which permits an easy derivation of the weight enumeration function of turbo codes relying on the weight enumeration function of its each component codes. Our tight bound derived here is based on the Sphere bound and on Verdu theorem. This new tight bound of the bit error probability for turbo codes is derived by refining the Sphere bound by means of the reduced value of the coefficients which apply Verdu theorem. This approach is simpler than other upper bound technique and is advantageous and extends the reliable region of for which the bound yields meaningful results. In order to demonstrate our tight bound, we analysis our tight bound and compare with other upper bounds and computer simulation results.