Agere Systems Inc.

Koninklijke Philips Corporation N.v.

Commissariat a L'energie Atomique

Lsi Corporation

Avago Technologies General IP (singapore) Pte. Ltd.

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Avago Technologies General IP Pte, Ltd.

Tim Schenk

Allert Van Zelst

Adriaan Kamerman

Jan Boer

Bas Driesen

Xiao-Jiao Tao

Isabella Modonesi

Lorenzo Feri

Oscar Garcia Morchon

Ronald Rietman

Ruud Vlutters

Dominique Morche

Javier Espina Perez

Robert John Kopmeiners

Kai Roland Kriedte

Pieter-Paul Severin Giesberts

Cédric Dehos

Cedric Dehos

Daniel Marin Goergen

Frits De Bruijn

Jan H Boer

There is provided a light detection system which is capable of determining in light embedded codes by detecting light in a scene which is illuminated by an illumination system () comprising one or more light sources () each providing a light contribution (I, I, I) comprising an embedded code (ID#, ID#, ID#) emitted as a temporal sequence of modulations in a characteristics of the light emitted. The light detection system comprises light detection means (), which are arranged for acquiring at least one image of the scene, where the image is acquired a plurality of temporal shifted line instances. Each line of the acquired image comprises an instance of the temporal sequence of modulations of the first embedded code. The light detection system further comprises means () for determining embedded codes from the spatial pattern of modulations.

Light detection system and method

A method and apparatus are provided for transmitting one or more symbols in a multiple antenna wireless communication system. Subcarriers from one or more symbols are interleaved across a plurality of antennas. The symbols may be, for example, long or short training symbols based on a single-antenna long or short training symbol, respectively, and wherein each subsequent subcarrier from the single-antenna training symbol is positioned in a training symbol for a logically adjacent antenna. One or more additional subcarriers may be inserted in at least one of the plurality of symbols to allow nulled subcarriers to be estimated using an interpolation-based channel estimation technique. The remaining portions of a header, as well as the data sequences of a packet, may also be diagonally loaded.

Method and apparatus for communicating symbols in a multiple input multiple output communication system using interleaved subcarriers across a plurality of antennas

For reducing and homogenizing an end-to-end delay of data packet transmissions in a large-scale wireless mesh network, a device, a system and a method are provided for controlling data packet transmission in the wireless network, wherein transmission parameters of an intermediate node are adjusted based on a distance between the intermediate node and a sender node.

Device and method for delay optimization of end-to-end data packet transmissions in wireless networks

A method and apparatus are provided for access point selection in wireless communication systems, such as wireless LANs. A disclosed wireless communication device includes a roaming process that selects an access point based on a measure of correlation on a channel to one or more surrounding access points. The roaming process selects an access point, for example, having the lowest correlation value. The roaming process may also consider the signal quality, channel delay spread or both in selecting an access point.

Method and apparatus for access point selection using channel correlation in a wireless communication system

A method for digital compensation of nonlinearities in a communication system that includes a transmitter, a transmission channel and a receiver, including: estimating the nonlinearities induced by the transmitter and/or the receiver, from at least one learning sequence received at the receiver and distorted by the nonlinearities, and compensating for the nonlinearities distorting a signal received at the receiver based on the estimating of the nonlinearities.

Method for the digital compensation of nonlinearities in a communication system and receiver device

A method and apparatus are disclosed for transmitting symbols in a multiple antenna wireless communication system, such that the symbols can be interpreted by a lower order receiver (i.e., a receiver having a fewer number of antennas than the transmitter). For example, subcarriers from one or more symbols can be transmitted such that each of the subcarriers are active on only one of the antennas at a given time. In one implementation, the subcarriers are diagonally loaded across logically adjacent antennas. The symbols can include one or more long training symbols and optionally a SIGNAL field that indicates a duration that a receiver should defer until a subsequent transmission. In this manner, a transmitter in accordance with the present invention may be backwards compatible with a lower order receiver and a lower order receiver can interpret the transmitted symbols or defer for an appropriate duration.

Methods and apparatus for backwards compatible communication in a multiple input multiple output communication system with lower order receivers

A method and apparatus are disclosed for transmitting symbols in a multiple antenna communication system according to a frame structure, such that the symbols can be interpreted by a lower order receiver (i.e., a receiver having a fewer number of antennas than the transmitter). The disclosed frame structure comprises a legacy preamble having at least one long training symbol and N-1 additional long training symbols that are transmitted on each of N transmit antennas. The legacy preamble may be, for example, an 802.11 a/g preamble that includes at least one short training symbol, at least one long training symbol and at least one SIGNAL field. A sequence of each of the long training symbols on each of the N transmit antennas are time orthogonal. The long training symbols can be time orthogonal by introducing a phase shift to each of long training symbols relative to one another.

Methods and apparatus for backwards compatible communication in a multiple antenna communication system using time orthogonal symbols

In a multiple-input, multiple-output (MIMO) system, a receiver is implemented with at least one additional receive path beyond the number of transmit antennas used to transmit the signals (e.g., wireless OFDM signals) received at the receiver. In one embodiment, the additional receive path is used to reduced co-channel interference (CCI) in the recovered OFDM signals. In particular, each receive path applies recursive filtering to generate separate subcarrier signals. A processor converts the separate subcarrier signals from the different receive paths into a first set of subcarrier signals corresponding to each transmitted OFDM signal, where each first set of subcarrier signals has desired signal and possibly CCI. The processor also generates a second set of subcarrier signals corresponding to the CCI. The processor subtracts portions of the second set of subcarrier signals from each first set of subcarrier signals to generate recovered OFDM signals having reduced CCI.

MIMO receivers having one or more additional receive paths

Symbol timing for a wireless communication system, such as a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) wireless LAN system, is determined by summing the powers for an appropriate set of channel impulse responses, integrating this power summation over an appropriate window (e.g., equivalent to the guard interval), and identifying the time at which the maximum integration occurs. Depending on the implementation, symbol timing can be determined for each receiver branch individually or for all receiver branches jointly. In either case, the determined symbol timing(s) can minimize the amount of inter-symbol and inter-channel interferences that are invoked in the system.

Symbol timing for MIMO OFDM and other wireless communication systems

Growing community of inventors

Eindhoven, Netherlands

Tim Schenk