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Coded asynchronous near-far resistant DS-CDMA receivers operating without synchronization
Stefan Parkvall,Erik G. Ström,Laurence B. Milstein +2 more
- pp 183-187
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TLDR
In this article, several receivers for data demodulation in an asynchronous direct-sequence code-division multiple access (DS-CDMA) system operating without prior knowledge of the propagation delays are proposed and compared.Abstract:
in this paper, several receivers for data demodulation in an asynchronous direct-sequence code-division multiple access (DS-CDMA) system operating without prior knowledge of the propagation delays are proposed and compared. Special attention is paid to the near-far problem, and the proposed schemes are numerically shown to be near-far robust. The near-far robustness is obtained by estimating the a priori unknown propagation delay using a subspace-based technique. Quantities obtained in the estimation procedure are subsequently used to design an interference suppression filter according to the minimum mean-squared error criterion. A simple two-state Viterbi algorithm is used for the data demodulation in the uncoded case. By extending the trellis used in the Viterbi algorithm, error correcting coding is easily implemented.read more
Citations
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Multiuser demodulation for DS-CDMA systems in fading channels
TL;DR: It is shown that the FIR detectors can be made near-far resistant under a given ratio between maximum and minimum received power of users by selecting an appropriate memory-length, and the iterative detectors are also shown to be applicable for parallel implementation.
Book ChapterDOI
Advanced CDMA for Wireless Communications
Markku Juntti,Savo Glisic +1 more
TL;DR: Some selected topics currently being subject of extensive research for applications in future code-division multiple-access (CDMA) networks are reviewed and a comprehensive review of the multiuser demodulation theory and technology is presented.
Journal ArticleDOI
Differential decorrelator: a new approach for designing CDMA linear detector
TL;DR: A new detector is proposed that can cancel the MAI in the received CDMA signal with a complexity that is independent on the number of the system's users with a simple structure that can work with synchronous and asynchronous system models.
References
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Maximum-likelihood sequence estimation of digital sequences in the presence of intersymbol interference
TL;DR: In this paper, a maximum likelihood sequence estimator for a digital pulse-amplitude-modulated sequence in the presence of finite intersymbol interference and white Gaussian noise is developed, which comprises a sampled linear filter, called a whitened matched filter, and a recursive nonlinear processor, called the Viterbi algorithm.
Journal ArticleDOI
Minimum probability of error for asynchronous Gaussian multiple-access channels
TL;DR: The results show that the proposed multiuser detectors afford important performance gains over conventional single-user systems, in which the signal constellation carries the entire burden of complexity required to achieve a given performance level.
Journal ArticleDOI
Crosscorrelation properties of pseudorandom and related sequences
TL;DR: This paper presents a survey of recent results and provides several new results on the periodic and aperiodic crosscorrelation functions for pairs of m-sequences and for Pair of related (but not maximal-length) binary shift register sequences.
Journal ArticleDOI
Multistage detection in asynchronous code-division multiple-access communications
TL;DR: A multiuser detection strategy for coherent demodulation in an asynchronous code-division multiple-access system is proposed and analyzed, showing that the two-stage receiver is particularly well suited for near-far situations, approaching performance of single-user communications as the interfering signals become stronger.
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