Analysis and design of IDMA systems based on SNR evolution and power allocation

Abstract

Abstract-We show that the performance of an interleavedivision multiple-access (IDMA) system can be assessed by tracking the signal-to-noise-ratio (SNR) evolution of the iterative chip-by-chip (CBC) detection process. Based on this we develop a power allocation technique for performance optimization. Very high throughput (say 8 bits/chip) is observed for IDMA without sophisticated channel coding. 1 Index Terms-CDMA, iterative detection, linear programming, multiuser detection, power allocation.

Power Optimization of IDMA Systems with Different Target BER Constraints

“…A heuristic approach of using the width of the tunnel as a parameter for convergence speed was presented in [6]. Optimization was done with linear programming which is only able to consider transfer functions but not the corresponding trajectory.…”

Channel estimation using an adaptive neuro fuzzy inference system in the OFDM-IDMA system

“…The combination of two schemes gathers the advantages of both systems that are the capability of solving intersymbol interference (ISI) and multiple access interference (MAI) problems [2,3]. ISI and MAI, two main obstacle in wireless communication systems, are prevented by the OFDM and IDMA parts, respectively [4,5]. In the OFDM-IDMA system, the signals belonging to different users are separated by the interleavers generated particularly for each user [6][7][8][9].…”

A game theoretic framework for decentralized power allocation in IDMA systems

“…Nonetheless, the study of distributed power allocation algorithms for IDMA is still an unsolved problem. The centralized power allocation (CPA) has been tackled by several authors (see [3], [4], and references therein). In these works, iterative multiuser detection/channel decoding is assumed at the receiver and the base station determines the power to be transmitted by each user, according to a global optimum criterion and typically having complete channel state information (CSI).…”

“…In this contribution, a novel framework to tackle the DPA problem in IDMA systems using tools from game theory is presented. The proposed approach assumes iterative multiuser detection/channel decoding at the receiver based on the chip-by-chip (CBC) algorithm [1], and relies on the signal to noise ratio (SINR) evolution technique [4] for non-heavily loaded systems.…”

“…This structure is known as CBC decoder and is described in [1]. The SINR at the input of the decoder can be estimated at each iteration of the CBC detection by means of the SINR evolution technique [4]. It is shown in [3] that in the steady state, the SINR of user k, denoted as γ k , converges to the solution to the following system of equations…”