Nokia Corporation

Other

Nokia Telecommunications Oy

William Marsh Rice University

Baylor College of Medicine

Behnaam Aazhang

Ashutosh Sabharwal

Mohammad Jaber Borran

Krishna Kiran Mukkavilli

Prabodh Varshney

Arnab Chakrabarti

Gang Xu

Jorma Lilleberg

Joseph R Cavallaro

Taiyun Chi

Alexandre De Baynast

Wayne Goodman

Sameer A Sheth

Fatima Ahsan

Raymond Cho

A method for minimally invasive deep brain simulation (DBS) involves obtaining a target location for the DBS, obtaining an anatomical model, and simulatively determining, for a set of antennas endocranially implanted at first positions and emitting electromagnetic waves differing by a frequency offset, a first envelope signal at the target location, using the anatomical model. The first envelope signal resulting from interference of the electromagnetic waves at the target location has an envelope signal frequency corresponding to the frequency offset.

Minimally invasive deep brain stimulation using electromagnetic waves

Thus, the exemplary embodiments of the invention describe methods, computer program products and apparatus that provide improved quantization, as may be useful within the context of a communication system (e.g., a wireless communication system) that has a relay node. In one non-limiting, exemplary embodiment, a method includes: receiving a transmission having source data from an information source; determining an estimate of the source data using a quantization technique based on maximizing data throughput; and transmitting a message including the determined estimate towards an information destination.

Methods, computer program products and apparatus providing improved quantization

A signal constellation for a multiple input/multiple output (MIMO) communication system when channel knowledge at the receiver is imperfect includes at least two (n&#x2212;1)-dimensional sub-constellations of points that together form an n-dimensional constellation, the number n representing real dimensions and n=2M where M is the number of transmit antennas. The n-dimensional spherical constellation may define a single sphere or a plurality of concentric subset spheres, and points between subsets are separated by a Kullback-Leibler distance rather than a Euclidian distance. Each sphere has sub-constellations that preferably are arranged in symmetric pairs that define equal numbers of points that lie in parallel planes, to allow recursive construction that minimizes computational complexity. An appropriate constellation may be chosen by ceasing a search once the optimum minimum distance stops increasing as a number of the concentric levels increases.

Partially coherent constellations for multiple-antenna systems

A first data symbol that includes a kdata bit is received over a multicarrier system. A first channel quality parameter is estimated for the first data symbol. A second data symbol that includes a retransmitted kdata bit is received. A second channel quality parameter for the second data symbol is estimated. A probable value of the kdata bit is determined based on both the first channel quality parameter and the second channel quality parameter. In response to an ARQ for data symbols communicated over a multicarrier system, the following are performed: determining channel quality parameters, each of the channel quality parameters corresponding to at least one of the transmitted data symbols; selecting a subset of the channel quality parameters exhibiting a worst quality; constructing a block of data symbols corresponding to the subset; and communicating the block of data symbols over a plurality of subcarriers.

Ordered retransmissions for ARQ in multicarrier systems

A method including transmitting a binary vector from a source node to a relay node and receiving a signal vector at the relay node. The method also includes compressing the signal at the relay node by multiplying the signal with a matrix using probabilities and converting output probabilities from the multiplying into retransmission signal amplitudes, the signal amplitude depending not only on a probability of a bit but on a transmission power constraint at the relay node. The method also includes transmitting, by the relay node, estimates of information from the source node to a destination node.

Variable rate soft information forwarding

The telecommunications system described herein implements a multi-rank beamformer for use in wireless systems equipped with multiple transmit and multiple receive antennas. The multi-rank beamformer uses finite-rate feedback of channel conditions to achieves close to theoretical performance indicated by the water-filling algorithm, while avoiding the computational complexity associated with space time codes. In addition, the multi-rank beamforming system described herein improves on the performance of unit rank beamforming methods by maintaining the gains over space time codes over a broader range of transmission rates.

Generalized m-rank beamformers for MIMO systems using successive quantization

Beamforming systems having a few bits of channel state information fed back to the transmitter benefit from low complexity decoding structures and performances gains compared with systems that do not have channel state feedback. Both unit rank and higher rank systems are implemented. Substantial design effort may be avoided by following a method of using functions formulated for space-time systems with the change that the channel coherence time is equated to the number of transmit antennas and the number of antennas in the space-time formulation is fixed at one.

Low complexity beamformers for multiple transmit and receive antennas

A signal constellation is optimized for trellis coded modulation in fast fading channels, where the receiver does not have perfect knowledge of the channel parameters. Specifically, the signal constellation is partitioned into 2mutually exclusive subsets, each preferably defining two points. Points within each subset are separated from one another by a distance between conditional distributions, preferably a Kullback-Leibler (KL) distance. For a block m=k+kof information bits input into a trellis coder, the kbits are trellis encoded into n bits (n&#x3e;k) and used to select a subset of the constellation. The kbit(s) is/are used to select a particular point within the subset. Because the inter-subset distance between points is a KL distance that is effectively greater than a Euclidean distance, error at the receiver is substantially reduced, especially at higher SNR. Using a KL distance ensures statistics of channel fading are inherent within the signal constellation.

Coded modulation for partially coherent systems

A multistage detector is disclosed that maximizes computation power while minimizing system delay. The differencing multistage detector receives signals from a plurality of users in a cell of a communications system and reduces the effect of multiple access interference to a signal from a desired user caused by interference from other users in the cell. The differencing multistage detector includes a plurality of stages, each stage including an interference canceller for removing intra-cell interference caused by the other users in the cell and producing an estimation output vector, wherein except for a first stage, the estimation output vector of a current stage is based on both a decision of the interference canceller of the current stage and the output from an interference canceller of a previous stage. The estimation output vector of a current stage is produced by combining the output from an interference canceller of a previous stage and the decision of the interference canceller of the current stage. Except for the first stage each interference canceller calculates an estimate of multi-user interference by computing a product of a cross-correlation of the received signals and a difference signal thereby reducing the number of multiplication operations required.

Growing community of inventors

Houston, TX, United States of America

Behnaam Aazhang