7082 results about "Interference (communication)" patented technology

A system and / or a method for detecting interference using correlation may be used in a communication system to protect against, or to report the presence of, narrowband interference, which has deleterious effects on the performance of the wideband communication system. The interference detection system described herein may be used to determine presence of narrowband interference by calculating correlation factors for a plurality of narrowband channels disposed within the wideband communication system and comparing the correlation factors with a threshold correlation factor.

A radio communication apparatus that performs first radio communication using a first channel among two first channels each having a first channel width, and second radio communication using a second channel having a second channel width that is wider than the first channel width and also having a channel width overlapping with the two first channels. The apparatus includes an interference detection device which detects that interference occurs in the first channel among the two first channels, and a frame generation unit which generates a notification frame that recommends the use of only the first channel width. An instruction unit instructs the frame generation unit to generate the notification frame when the occurrence of interference is detected by the interference detection device. A frame transmission unit transmits the notification frame generated from the frame generation unit in response to the instruction from the instruction unit.

A system for compensating for in-phase and quadrature (I / Q) imbalances for multiple antenna systems (MAS) with multi-user (MU) transmissions (defined with the acronym MU-MAS), such as distributed-input distributed-output (DIDO) communication systems, comprising multicarrier modulation, such as orthogonal frequency division multiplexing (OFDM). For example, one embodiment of the system comprises one or more coding modulation units to encode and modulate information bits for each of a plurality of wireless client devices to produce encoded and modulated information bits; one or more mapping units to map the encoded and modulated information bits to complex symbols; and a MU-MAS or DIDO IQ-aware precoding unit to exploit channel state information obtained through feedback from the wireless client devices to compute MU-MAS or DIDO IQ-aware precoding weights, the MU-MAS or DIDO IQ-aware preceding unit precoding the complex symbols obtained from the mapping units using the weights to pre-cancel interference due to I / Q gain and phase imbalances and / or inter-user interference.

Adaptive antenna array techniques for use in an orthogonal frequency division multiplexed spread-spectrum multi-access (OFDM-SSMA) cellular wireless system or other type of wireless communication system. A base station of the system includes an antenna array and a base station receiver. The base station receiver implements an adaptive antenna gain algorithm which estimates a spatial covariance matrix for each of K mobile stations communicating with the base station. The spatial covariance matrix for a given one of the mobile stations is determined at least in part based on a unique hopping sequence of the mobile station, and provides a correlation between signals received from the mobile station at different antenna elements within the antenna array. An average spatial covariance matrix for a set of received signals is also generated. The individual spatial covariance matrices and the average spatial covariance matrix are processed to generate an estimate of an interference matrix for the K mobile stations, and the estimate of the interference matrix is further processed to generate array responses for each of the mobile stations. The array response for a given mobile station is processed to determine an antenna weighting which is applied to a signal received from the given mobile station in order to facilitate detection of a corresponding transmitted symbol.

Lightweight, low cost, high density electrical connectors are disclosed that provide impedance controlled, high-speed, low interference communications, even in the absence of shields between the contacts, and that provide for a variety of other benefits not found in prior art connectors, such as low insertion loss. Signal contacts and ground contacts within the connectors can be scaled and positioned relative to one another such that a differential signal in a first differential signal pair produces a high field in the gap between the contacts that form the signal pair and a low field near an adjacent signal pair. Consequently, cross talk between adjacent signal contacts can be limited to acceptable levels for the particular application. In such connectors, the level of cross talk between adjacent signal contacts can be limited to the point that the need for (and cost of) shields between adjacent contacts is unnecessary, even in high speed, high signal integrity applications.

A frequency and protocol agile wireless communication product, and chipset for forming the same, including a frequency agile transceiver, a digital interface circuit for interconnecting the radio transceiver with external devices, protocol agile operating circuit for operating the radio transceiver in accordance with one of the transmission protocols as determined by a protocol signal and an adaptive control circuit for accessing a selected wireless communication network and for generating the frequency control signal and the protocol control signal in response to a user defined criteria Among the possible user defined criteria would be (1) the cost of sending a data message, (2) the quality of transmission link (signal strength, interference actual or potential), (3) the potential for being bumped off of the system (is service provider at near full capacity), (4) the security of transmnission, (5) any special criteria which the user could variably program into his omni-modal wireless product based on the user's desires or (6) any one or more combinations of the above features that are preprogrammed, changed or overridden by the user. The disclosed invention allows wireless service providers to broadcast electronically as part of any “handshaking” procedure with a omni-modal wireless product information such as (1) rate information and (2) information regarding system operating characteristics such as percent of system capacity in use and / or likelihood of being dropped. The disclosed invention creates a user oriented source enrollment and billing service in the wireless data market by establishing uniform standard for “handshakes” to occur between cell service providers and omni-modal wireless products. In addition, the disclosed invention can be implemented on a standard chip or chipset including a radio transceiver specifically designed to be used in all types of omni-modal wireless products.

A wireless communications adapts its mode of operation between spatial multiplexing and non-spatial multiplexing in response to transmission-specific variables. An embodiment of a wireless communications system for transmitting information between a base transceiver station and a subscriber unit includes mode determination logic. The mode determination logic is in communication with the base transceiver station and the subscriber unit. The mode determination logic determines, in response to a received signal, if a subscriber datastream should be transmitted between the base transceiver station and the subscriber unit utilizing spatial multiplexing or non-spatial multiplexing. In an embodiment, the mode determination logic has an input for receiving a measure of a transmission characteristic related to the received signal. In an embodiment, the mode determination logic includes logic for comparing the measured transmission characteristic to a transmission characteristic threshold and for selecting one of spatial multiplexing and non-spatial multiplexing in response to the comparison of the measured transmission characteristic to the transmission characteristic threshold. In an embodiment, the transmission characteristic includes at least one of delay spread, post-processing signal-to-noise ratio, cyclical redundancy check (CRC) failure, residual inter-symbol interference, mean square error, coherence time, and path loss. By adapting the mode of operation in response to transmission-specific variables, the use of spatial multiplexing can be discontinued in unfavorable conditions. Additionally, because the wireless communications system can adapt its mode of operation between spatial multiplexing and non-spatial multiplexing, the communications system is compatible with both subscriber units that support spatial multiplexing and subscriber units that do not support spatial multiplexing.

A receiver of the present invention addresses the need for improved interference suppression without the number of transmissions by the power control system being increased, and, to this end, provides a receiver for a CDMA communications system which employs interference subspace rejection to tune a substantially null response to interference components from selected signals of other user stations. Preferably, the receiver also tunes a substantially unity response for a propagation channel via which a corresponding user's signal was received. The receiver may be used in a base station or in a user / mobile station.

The invention provides a technical scheme which is applied to a cellular network for mobile communication. A D2D (Device-to-Device) technology is applied to the cellular network, and thereby a D2D user pair is allowed to simultaneously multiplex multiple cellular network user resources to communicate. In addition, a mode for maximizing system data rate is selected from the scheme and a traditional scheme to realize resource sharing. The scheme proposed by the invention cannot cause great interference to certain cellular user and is easy to realize and relatively flexible to apply in actuality. The invention provides a method for simultaneously multiplexing multiple cellular user resources by single D2D user pair in the cellular network with D2D communication, which can be used for increasing the frequency spectrum efficiency of a system whole (including cellular communication and D2D communication) under the condition of guaranteeing the lowest communication rate of a cellular user. The method provided by the invention has strong actual operability.

A family of methods for interference averaging in multicarrier systems, such as orthogonal frequency division multiplexing (OFDM) systems. The methods can provide interference averaging in situations where an interfering co-channel is either partially or fully loaded. For partially loaded systems, subcarrier puncturing, frequency domain repetition, time domain repetition, and hybrid time-frequency repetition schemes are provided. For systems using adaptive modulation / coding rates, lower rates and transmit power can be selected in order to perform interference averaging in time-spread and frequency-spread OFDM schemes. In systems with downlink power control, frequency domain mixing can be used to perform interference averaging.

Wireless communications structures and methods are provided that utilize frequency domain spatial processing. Structure is included that receives and transmits signals from an array of Mβ antennas wherein the antennas are connected to M switches in groups of β. Each switch is connected to a single spatial processing channel and β antennas and each spatial processing channel is assigned complex multiplicative factor(s), or weight(s), that enhance overall system performance in the presence of interference and propagation-related impairments such as multipath fading.

In a mobile communication system, each base station is provided with an array antenna, a section for estimating the respective directions of one or more mobile stations with which the base station is in communication, based on estimated incoming directions of radio waves received from these mobile stations, and sections for operating on respective signals of the antenna elements constituting the array antenna such as to shape the radiation pattern of the antenna to form peaks of directivity which are oriented in the estimated directions of these mobile stations, and can include a capability for shaping these peaks in accordance with estimated positions of these mobile stations, thereby minimizing interference between transmissions from that base station and communication being executed between other adjacent stations of the system, and minimizing the number of different transmission frequencies required in the overall system.

A method and medium tangibly embodying the method of constructing a lookup table of modes for encoding data for transmission in a wireless communication channel from a transmit unit to a receive unit by using at least one quality parameter of the data and its first-order and second-order statistical parameters to arrange the modes in the lookup table. The first-order and second-order statistical parameters can be determined from a simulation of the wireless communication channel or from field measurements of the wireless communication channel. The modes in the lookup table are ordered by a target value of a communication parameter such as PER, BER, data capacity, signal quality, spectral efficiency, throughput or another suitable communication parameter set to achieve a desired quality of service. The quality parameter selected is conveniently a short-term quality parameter such as signal-to-interference and noise ratio (SINR), signal-to-noise ratio (SNR) or power level. During use adjustments depending on the instantaneous condition of the channel can be used to tune the lookup table.