R. Muller

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The spectral efficiency of practically oriented vector precoding schemes for the Gaussian multiple-input multiple-output (MIMO) broadcast channel is analyzed in the large system limit. Considering discrete complex input alphabets, the transmitter is assumed to comprise a linear front-end combined with nonlinear precoding, that minimizes the transmit energy(More)
We apply the replica method to analyze vector pre-coding, a method to reduce transmit power in antenna array communications, in the limit of an infinite number of dimensions of the signal vector. The analysis applies to a very general class of channel matrices. The statistics of the channel matrix enter the transmitted energy per symbol via its R-transform.(More)
The large system performance analysis of linear multiuser detectors (e.g. MMSE, MSWF, multistage detectors) for asynchronous CDMA systems is provided. While the performance of synchronous systems with square-root waveforms is independent of the chip bandwidth, the performance of asynchronous systems depends on the pulse shape and the bandwidth. It increases(More)
The so-called ldquoreplica methodrdquo of statistical physics is employed for the large system analysis of vector precoding for the Gaussian multiple-input multiple-output (MIMO) broadcast channel. Focusing on discrete complex input alphabets, the transmitter is assumed to comprise a linear front-end combined with nonlinear precoding, that minimizes the(More)
We propose a method for vector precoding suited to singular multiple-input multiple-output (MIMO) channels were the number of data streams is larger than the number of transmit antennas. We calculate the probability that our method, due to the channel singularity, fails to provide the data without crosstalk to the receiver, analytically, and show that this(More)
We derive asymptotic upper bounds of the performance of a one-shot MMSE multiuser detector (MUD) and an optimal MUD in frequency-selective fading DS-CDMA channels with imperfect CSI at the receiver, using the replica method. We find that the performance bound of the one-shot MMSE MUD is indistinguishable from the performance of the one-shot LMMSE MUD(More)
In this contribution, the double directional model derived within the maximum entropy framework in M. Debbah and R. Muller (2003) is studied. For a given power profile, an asymptotic analysis (in the number of antennas) is conducted on the achievable transmission limit using tools of random matrix theory. It is shown in particular that the optimal(More)
A noisy MIMO channel operating under a strict complexity constraint at the receiver is introduced. According to this constraint, detected bits, obtained by performing hard decisions directly on the channel's matched filter output must be the same as the transmitted binary inputs. In this simple detection scheme the complexity of detection is outsourced from(More)
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(More)
We consider the uplink and the downlink of a multiuser wireless system with one base station and K user terminals. We model wideband transmission by considering M parallel subchannels, each of which is affected by fading. The fading processes in each subchannel are slowly time-varying with respect to the coding block length. Hence, in order to maintain(More)