Broadband Radio Access Network Channel Identification and Downlink MC-CDMA Equalization

Abstract

In this paper we propose a new algorithm based on third order cumulants, for MultiCarrier Code Division Multiple Access (MC-CDMA) system equalization. In order to test its efficiency, we have compared with the (CUM-AZ) algorithm proposed in the literature, for that we considered five practical frequency-selective fading channels, called Broadband Radio Access Network (BRAN A, BRAN B, BRAN C, BRAN D, and BRAN E), normalized for (MC-CDMA) system, excited by non-Gaussian sequences. In the part of (MC-CDMA), we use the zero forcing (ZF) and the minimum mean square error (MMSE) equalizers techniques after the channel identification to correct the channel's distortion. The simulation results, in noisy environment and for different signal to noise ratio (SNR), are presented to illustrate the performance of the proposed algorithm.

Channel Identification Based on Cumulants, Binary Measurements, and Kernels

“…The estimated parameters shown in Figures 12,13,15,16,18, and 19 evidently show that both KLMS and KRLS achieved higher prediction accuracy than the binary-measurement-based algorithms and cumulant-based algorithms for all values of SNR. Meanwhile, the performance of KRLS was also marginally better than that of KLMS, although it had a greater computational complexity.…”

“…The synchronization required between the transmitter and the receiver is also a problem in the communication process. To handle this phase estimation problem, some authors have employed higher-order cumulants (HOCs) in order to investigate the reliability of these techniques if the channel is influenced by a colored noise [2,[9][10][11][12][13][14][15][16]. HOCs are a significant topic with multiple applications in the field of systems theory, such as in digital signal recognition [17], automatic modulation classification of real signals [18], and space-time block code identification [19].…”

Using Least Mean p-Power Algorithm to Correct Channel Distortion in MC-CDMA Systems

“…The complex symbol a i of each user i is, firstly, multiplied by each chip c i,k of the Walsh-Hadamard spreading code, and then applied to the modulator of the multicarriers. Each subcarrier transmits an element of information multiplied by a code chip of that subcarrier (an overview of MC-CDMA systems can be found in [6], [12]- [14]). Figure 2 shows the MC-CDMA modulator in a scenario where the spreading code has a length L c equal to the number of subcarriers N p , based on the hypothesis of L c being equal to N p , and the expression of the signal transmitted at the output of the modulator is given by:…”

Compensation of Fading Channels Using Partial Combining Equalizer in MC-CDMA Systems

“…Secondly, cumulants are useful in identifying non-minimum phase channels when the input is non-Gaussian and is contaminated by Gaussian noise. The problem of the blind identification of the Broadband Radio Access Network (BRAN) channels, normalized by the European Telecommunications Standards Institute (ETSI) [7]- [8], and downlink MC-CDMA equalization using higher order cumulants was proposed by several authors [9]- [12]. In this contribution, authors present a partial combining equalizer for downlink MC-CDMA systems equalization, for that is in the one hand, the problem of the blind identification of (BRAN A) channel using the proposed algorithm is considered, and in the other hand the presented equalizer after the channel identification to correct the channel's distortion is used.…”