An approximate formula for bit error rate of turbo code

Abstract

Bit Error Rate (BER) is a significant metric extensively used in the performance evaluation of digital communication systems. Although BER can always be estimated through computer simulation, closed form expressions are often desirable in many scenarios. In this paper we propose an approximate formula for the BER of Turbo codes. With the proposed approximation, BER of Turbo codes under additive white Gaussian noise (AWGN) channel can be expressed as a product of two Gaussian Q functions with a scaling factor only depends on the signal-to-noise ratio (SNR). Simulation results show that the approximation error of the proposed formula is less than 0.3 dB both in AWGN and block Rayleigh fading channel.