Claude Simon

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Unilateral vestibular lesion, as acoustic neuroma and its surgical removal, leads to impaired balance control. After initial vertigo and postural instability corresponding to unilateral vestibular deafferentation, improvement in symptoms and global balance functions occurs by a process called vestibular compensation. In this respect, this prospective study(More)
Vestibular compensation after unilateral vestibular deafferentation is modulated by certain individual characteristics, such as pre-operative visual neurosensory preference or vestibular pattern. Physical activity (PA) allows the implementation of new sensorimotor and behavioral strategies leading to an improvement of balance control. This study aimed to(More)
Recommended by David Gesbert This paper gives an overview and a comparison of recent feedback quantization schemes for linear precoded spatial multiplexing systems. In addition, feedback compression methods are presented that exploit the time correlation of the channel. These methods can be roughly divided into two classes. The first class tries to minimize(More)
This paper presents two novel methods to optimally compress the feedback for spatial multiplexing with linear precoding. The methods exploit the time correlation of the channel and the knowledge of the previously fed back precoder matrices to estimate the conditional probabilities of the different possible feedback indices. These probabilities are then used(More)
Combining spatial multiplexing with linear unitary pre-coding allows for high data rates, but requires a feedback link from the receiver to the transmitter. We focus on quan-tizing and feeding back the precoder itself, since it outper-forms quantized channel feedback. More specifically, we propose a modified precoder quantization approach that out-performs(More)
— In this paper we apply Predictive Vector Quanti-zation (PVQ) to quantize time-correlated broadcast channels. PVQ exploits the time-correlation of the channel to reduce the quantization error of the channels, and thus to improve the sum rate of the system. PVQ predicts the actual channel based on a number of previous channels, and then quantizes the(More)
In this paper, we discuss different options for quantized feedback and feedback reduction for a precoded spatial-multiplexing multiple-input multiple-output (MIMO) system in a time-varying channel. The novel contributions of this paper are a quantized feedback strategy based on the bit-error-rate (BER) of a linear receiver, and two new feedback reduction(More)
In this paper we extend feedback compression schemes for precoded spatial multiplexing multiple-input multiple-output (MIMO) systems to adapt to changing channel characteristics. The presented schemes use the past feedback to estimate the conditional probability of a precoder occurrence given the last feedback at runtime. These probabilities are then used(More)
The time-course of central adaptive mechanisms after vestibular schwannoma surgical removal allows, 3 months after surgery (middle term), a satisfactory recovery of balance control. However, the long-term evolution of postural control beyond the end of usual medical follow-up remains unknown. This longitudinal prospective study aimed to assess the long-term(More)