A new polynomial approximation for Jν Bessel functions

The η-μ/gamma composite fading model

“…The algebraic form of (9) is relatively simple, however, the fact that the series has an infinite form raises the need for approximate asymptotic solutions, [8]. Based on that, the authors in [8] derived a useful polynomial approximation for I n (x) that, importantly, retains the simple algebraic form of (9).…”

Wireless Energy Harvesting Using Signals From Multiple Fading Channels

“…It was reported in [26] that this approximation is very accurate for small values of x, which is the case for the wireless signal received by the energy harvester. For example, for I 0 (x), the error is less than 4% when 0 < x < 12 and n 0 = 20 [26, Fig.…”

“…where Γ(·) is the Gamma function [25] and 2n 0 is the order of a Chebyshev polynomial used to approximate the Bessel function [26]. It was reported in [26] that this approximation is very accurate for small values of x, which is the case for the wireless signal received by the energy harvester.…”

“…Fig. 2 compares different approximations to the CDF of P M L1 in (26). In this figure, we set x i = 1, 2α…”

“…To obtain a closed-form expression, first, the approximation to the Bessel functions proposed in [26] is used as…”