Distribution of Instantaneous Power in Single Carrier Signal with Independent I/Q Components

This paper investigates the statistical distribution of instantaneous power (IP) in pulse-shaped single-carrier (SC) modulation with independent I/Q components. Such knowledge is required due to the nonlinearities that may appear in the whole communication track, especially that of the power amplifier (PA). Exact analytical derivation of the distribution is an open problem. The existing works rely on Monte-Carlo simulations or on complex numerical analysis. In this paper we propose a straightforward method, based on numerical integration, to evaluate the complementary cumulative distribution function (CCDF) of IP by using characteristic function approach. Error analysis of the proposed numerical approach is given. It is shown that by investing relatively small computation power in the proposed numerical solution we can derive the CCDF of IP with high and controlled accuracy.