A Low-Complexity Semi-Analytical Approximation to the Block Error Rate in Nakagami-m Block Fading Channels

There are few analytical formulas that can be used for calculating the block error rate (BLER) in block fading channels. Thus, an estimate of the BLER is often obtained using numerical methods. One such method is the threshold method which assigns 0 or 1 to the instantaneous BLER given the signal to noise ratio (SNR) level. It has been shown that utilizing such a method results in an accurate approximation of the BLER in Nakagami-m block fading channels for a wide range of m. In this work, we consider a recently proposed simple method of obtaining the threshold and study the effect of adopting different physical layer and channel parameters on that threshold. We show that, while the value of this threshold depends on the modulation, coding, and block size, it is almost unaffected by the m parameter of Nakagami-m channels for a wide range of practical values. In addition, for a given modulation and coding method, the threshold is shown to be a simple function of block size. As a result, the computational complexity required to obtain the threshold can be significantly reduced.