A fuzzy logic system for interference rejection in code division multiple access

Bas, Joan; Neira, Ana Pérez

doi:10.1109/fuzz.2003.1206567

Cited by 7 publications

(4 citation statements)

References 12 publications

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“…From Equation 13 we observe that in high SNR scenarios the output of the fuzzy system corresponds to the interference state with the highest maximum fuzzy basis function. Therefore, the fuzzy basis functions have the same role as the probability density functions of the MAP canceler.…”

Section: Optimum Cancelation and Its Fuzzy Approximationmentioning

confidence: 96%

“…The previous sections introduce the different structures in fuzzy logic that could implement Equation 13. Nevertheless, the previous strategies are either static (hierarchical and nonsingleton) or time-consuming (genetic algorithms, simulated annealing, and cooperative strategy).…”

Section: Adaptive Weightsmentioning

confidence: 98%

“…At this point we have to remark that the fuzzy canceler is related to the CM and MAP ones. Observing Equation 13, if the centers of the input membership functions a j, t are the states of the multiple access noise v j, t and the input membership functions and the noise distribution have the same shape, then the fuzzy canceler tends to the CM one. Similarly, the fuzzy canceler derives to the MAP one if the variance of the noise~s w 2 ) is small enough.…”

Section: Optimum Cancelation and Its Fuzzy Approximationmentioning

confidence: 98%

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A scalable fuzzy interference canceler for DS-CDMA systems

Bas

Neira

2004

Int. J. Intell. Syst.

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The spread spectrum modulation presents a more robust interference rejection capability than non-code-based modulations. However, the increase of the communication services has augmented the power of the interference signals. One example is unlicensed bands such as the 2.4-2.5 GHz one, where the DS-CDMA communications of the IEEE 802.11b standard are interfered with by other Industrial Scientific and Medical (ISM) services. One way of improving the interference robustness of the DS-CDMA receivers is introducing an interference canceler (IC) before the despreading stage. The optimum criterion to estimate or detect the interference is the maximum-a-posteriori (MAP) one. However, it requires a high computational burden and a complete knowledge of the statistical model, which reduce its feasibility. To overcome these drawbacks this article proposes an interference canceler based on Fuzzy Logic that allows (1) suppressing both analog and digital interferences, and (2) easily controlling the complexity versus performance trade-off. In other words, the design of the fuzzy canceler follows a down/ top strategy; that is, a first low complex design is possible just departing from linguistic information and, in a second stage, we refine it, incorporating the available statistical information into its structure. Finally, to assess the proposed fuzzy canceler we have derived asymptotic performance bounds.

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Section: Optimum Cancelation and Its Fuzzy Approximationmentioning

confidence: 96%

Section: Adaptive Weightsmentioning

confidence: 98%

Section: Optimum Cancelation and Its Fuzzy Approximationmentioning

confidence: 98%

See 1 more Smart Citation

A scalable fuzzy interference canceler for DS-CDMA systems

Bas

Neira

2004

Int. J. Intell. Syst.

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“…More specifically, (Daffara, 1995) and (Drake & Prasad, 1999) used fuzzy logic to track phase error detectors in synchronization, while (Perez-Neira & Lagunas, 1996) and (Perez-Neira et al, 1997) improved detection results by means of this technique. Finally, (Bas & Perez-Neira, 2003) applied fuzzy logic to interference rejection. These applications are based in the same principles that the one presented in this chapter; the wide knowledge of a system performance by the designer, which fuzzy logic helps to translate to a closed control system.…”

Section: Fuzzy Logic As An Acquisition Controlmentioning

confidence: 99%