Minimum probability of error for asynchronous Gaussian multiple-access channels
IEEE Transactions on Information Theory
Fundamentals of statistical signal processing: estimation theory
Fundamentals of statistical signal processing: estimation theory
Multiuser Detection
Toeplitz and circulant matrices: a review
Communications and Information Theory
Random sequence multisets for synchronous code-division multiple-access channels
IEEE Transactions on Information Theory
Spectral efficiency of CDMA with random spreading
IEEE Transactions on Information Theory
Linear multiuser receivers: effective interference, effective bandwidth and user capacity
IEEE Transactions on Information Theory
IEEE Transactions on Information Theory
Optimal sequences and sum capacity of synchronous CDMA systems
IEEE Transactions on Information Theory
IEEE Transactions on Information Theory
IEEE Transactions on Information Theory
Large system performance of linear multiuser receivers in multipath fading channels
IEEE Transactions on Information Theory
IEEE Transactions on Information Theory
The impact of frequency-flat fading on the spectral efficiency of CDMA
IEEE Transactions on Information Theory
IEEE Transactions on Information Theory
A statistical-mechanics approach to large-system analysis of CDMA multiuser detectors
IEEE Transactions on Information Theory
MMSE detection in asynchronous CDMA systems: an equivalence result
IEEE Transactions on Information Theory
Design of reduced-rank MMSE multiuser detectors using random matrix methods
IEEE Transactions on Information Theory
On the capacity loss due to separation of detection and decoding
IEEE Transactions on Information Theory
Mutual information and minimum mean-square error in Gaussian channels
IEEE Transactions on Information Theory
Randomly spread CDMA: asymptotics via statistical physics
IEEE Transactions on Information Theory
Optimal sequences and sum capacity of symbol asynchronous CDMA systems
IEEE Transactions on Information Theory
A Systematic Approach to Multistage Detectors in Multipath Fading Channels
IEEE Transactions on Information Theory
An asymptotic analysis of band-limited DS/SSMA communication systems
IEEE Transactions on Information Theory
CDMA Systems With Correlated Spatial Diversity: A Generalized Resource Pooling Result
IEEE Transactions on Information Theory
Asynchronous CDMA systems with random spreading-part II: design criteria
IEEE Transactions on Information Theory
Hi-index | 754.90 |
Spectral efficiency for asynchronous code division multiple access (CDMA) with random spreading is calculated in the large system limit allowing for arbitrary chip waveforms and frequency-flat fading. Signal-to-interference and noise ratios (SINRs) for suboptimal receivers, such as the linear minimum mean square error (MMSE) detectors, are derived. The approach is general and optionally allows even for statistics obtained by undersampling the received signal. All performance measures are given as a function of the chip waveform and the delay distribution of the users in the large system limit. It turns out that synchronizing users on a chip level impairs performance for all chip waveforms with bandwidth greater than the Nyquist bandwidth, e.g., positive roll-off factors. For example, with the pulse shaping demanded in the UMTS standard, user synchronization reduces spectral efficiency up to 12% at 10 dB normalized signal-to-noise ratio. The benefits of asynchronism stem from the finding that the excess bandwidth of chip waveforms actually spans additional dimensions in signal space, if and only if the users are desynchronized at chip-level. The analysis of linear MMSE detectors shows that the limiting interference effects can be decoupled both in the user domain and in the frequency domain such that the concept of effective interference spectral density arises. This generalizes and refines Tse and Hanly's concept of effective interference. In Part II, the analysis is extended to any linear detector that admits a representation as multistage detector and guidelines for the design of low complexity multistage detectors with universal weights are provided.