72results about How to "Cancel any interference" patented technology

An apparatus and a method for controlling interference in a wireless communication system are provided. The method includes receiving a signal of a DownLink (DL) frequency band that is adjacent to an UpLink (UL) frequency band supported by a User Equipment (UE), measuring a Received Signal Strength Indicator (RSSI) of the DL frequency band signal, comparing the measured RSSI with a threshold value, and, if the measured RSSI is less than the threshold value, limiting UL transmission.

An Apparatus and a method for interference cancellation in a wireless communication system are provided. When a resource of an Interference Cancellation (IC) zone is allocated to a terminal traveling in a service coverage, resource allocation information relating to an IC zone of neighbor cells is gathered. Resource allocation information is generated relating to the resource allocated to the terminal comprising resource allocation information of the IC zone of the neighbor cells. The resource allocation information relating to the resource allocated to the terminal is transmitted to the terminal. Accordingly, when the interference is present, the interference cancellation is carried out to reduce the load on the terminal and enhance the reception performance.

A method for operating a Mobile Station (MS) in a Multiple Input Multiple Output (MIMO) wireless communication system is provided. The method includes measuring channel quality for a serving Base Station (BS), if the channel quality is less than a threshold, measuring interference power from one or more neighbor BSs, determining a Precoding Matrix Index (PMI) and a priority metric for each neighbor BS, and feeding back at least one of the PMI, a PMI type indicator, the priority metric, and the channel quality to the serving BS.

A communication node for relaying a signal between a source node and a destination node is disclosed. The communication node includes: a relay signal generation unit configured to generate a transmit signal by reducing, from a receive signal, an interference signal from another communication node and performing a process such that the transmit signal is not received as an interference signal by another communication node.

This invention is related to a cognitive Multi-Input Multi-Output (MIMO) radio frequency (or laser) radar with large-area synchronized multi-dimensional hopping spread spectrum and Interference-Free Windows (IFWs) for autonomous vehicles comprising of (1) analog component; (2) digital baseband component; (3) multi-dimensional hopping code generator; (4) large-area time synchronization; (5) cooperative IFW; and (6) cognitive engine. The new MIMO radar can provide interference-free environmental perception intelligently by the multi-dimensional IFWs formulated by beat-frequency hopping, beat-time hopping, discrete sequence (DS), cooperative IFW, array processing, and image denoising and fusion, etc. This invention increases the frequency efficiency greatly, and be applied to autonomous vehicles and robotics under sparse, dense, mixed autonomous and human driving, or completely autonomous driving environments.

Methods and systems for cancelling interference in an analog communication signal are provided. The method includes receiving an analog communication signal including interference caused by a deterministic interference source, generating a digital interference signal corresponding to the interference caused by the deterministic interference source, converting the digital interference signal into a corresponding analog interference signal, and subtracting the analog interference signal from the analog communication signal.

A method for reducing multiple access interference (MAI) in a code division multiple access (CDMA) spread spectrum receiver assigned a number of codes which also despreads the received signal with the remaining codes of the same spreading factor. For forward link transmission with orthogonal codes, as in 3GPP and 3GPP2, interferers using larger spreading factors than the one used by the referenced mobile will have codes that are formed from the orthogonal codes of the same spreading factor as the multicodes corresponding to the referenced mobile. As a consequence, in a multipath environment, the output of a despreader using any of these remaining orthogonal codes will provide an estimate of the composite interference attributed to signals, if any, using codes that partly comprise the corresponding orthogonal code. No decisions are made for the previous despreader's output because it corresponds to a sum of interferers with unknown powers. However, this soft output can be re-spread and subtracted from the received signal prior to despreading, thereby removing the corresponding composite interference. This can significantly improve the performance of a receiver performing interference cancellation of both assigned and interfering signals, especially when the interfering signals have a substantial total power.

A duplexer for a communication device having a transmission unit, a reception unit and a shared antenna is disclosed. The duplexer comprises a first signal path between the transmission unit and the reception unit, the first signal path comprises a filter unit filtering the reception signal, the filtering unit provides a filtered signal to the reception unit. The duplexer further comprises a second signal path between the transmission unit and the reception unit. The second signal path comprises a cancellation unit which receives a sample of the transmission signal and produces a compensation signal. The injection of the compensation signal to the first signal path reduces the leakage signal, thereby producing a substantially leakage-free reception signal.

An apparatus and a method for interference cancellation in a transmitting end of a multi-antenna system are provided. A precode is generated which maximizes a diversity gain of one or more receive antennas using channel information of the receive antennas to be serviced. Transmit powers of the receive antennas are updated by taking into account a power loss and a shaping loss according to a dirty paper coding. Transmit signals are precoded by updating the precode according to the updated transmit powers. The dirty paper coding is performed on the precoded transmit signals to be transmitted to the receive antennas.

A receiving process method of a receiving apparatus used in a mobile communication system is provided in which a sending apparatus sends a plurality of code channels as code channel groups to which spreading codes are assigned to a receiving apparatus, and the receiving apparatus receives the code channels. The receiving process method includes, when spreading codes used for the code channel groups are orthogonal code sequences, generating received spreading signal sequences of the code channel groups according to the number of received paths. The receiving process method further includes removing received spreading signal sequences of a received path of own code channel group of the receiving apparatus which should be removed from the received signals.

An apparatus and method for interference cancellation in multiple-antenna communication system is disclosed. Accordingly, a receiver of a multiple-antenna communication system cancels interference by selecting either a multiple-symbol processing scheme or a single-symbol processing scheme depending on a signal type, thereby improving performance of the communication system.

A Macro-Diversity HandOver (MDHO) solution based on multi-User MIMO is provided. Multiple base stations (BSs) serve the MDHO zone. By jointly precoding the modulated signals to be sent, the multiple BSs send the precoded signals to the multiple mobile stations (MSs) over the same time-frequency resources. The signal to be sent is transmitted to the multiple MSs in the MDHO zone. Due to the adoption of the precoding technique, each MS makes no or small interference to other MSs. Since the multiple BSs that serve one MDHO zone serve multiple MSs over the same time-frequency resources, the system capacity in the MDHO zone is greatly improved.

The present invention provides a method for interference cancellation in a wireless communication system. One embodiment of a method includes accessing information indicative of one or more first signals transmitted by one or more first mobile units from one or more first sectors. The method also includes accessing information indicative of one or more second signals transmitted by one or more second mobile units from one or more second sectors different than the first sectors. The method further includes canceling interference caused in the second signal(s) by the first signal(s) using the accessed information indicative of the first signal(s) and the second signal(s). The method also includes jointly scheduling and allocating resources to one or more mobile stations in one or more sectors of one or more base stations.

A system and method are provided for canceling interference present in a local channel signal received at a receiver. The system includes a controller and a finger demodulator assembly. The controller is capable of selecting at least one interfering pilot channel signal that has a signal strength above a threshold, where the selected interfering pilot channel signals comprises an interfering set of pilot channel signals. The finger demodulator assembly can then be capable of producing a corrected local channel signal based upon the interfering set of pilot channel signals during the idle state and/or access state.

Provided are methods and systems of using division-free duplexing (DFD) to reduce rendezvous time between two or more cognitive radio devices. The cognitive radio devices may opportunistically use available frequency spectra by communicating over available channels. To communicate, a first device may rendezvous with a second device by transmitting a beaconing signal over a frequency on which the second device is listening. DFD techniques may enable each of the devices to listen to a channel while concurrently transmitting beacon signals over the same channel. As periods of listening and periods of transmitting over the same channel need not be separated due to the transmitter cancelling approach used in DFD techniques, rendezvous time may be significantly reduced. Further, embodiments include a generalized DFD (GDFD) approach wherein devices listen to a broad band of frequencies, thus further reducing rendezvous time.

An apparatus and a method for interference cancellation in a wireless communication system are provided. The method includes receiving channel information from one or more terminals; classifying the terminals into terminals interfered by a neighbor cell and terminals not interfered by the neighbor cell based on the channel information of the terminals; and allocating the terminals interfered by the neighbor cell and the terminals not interfered by the neighbor cell into different resource regions. The transmitter forms the beam taking into consideration the neighbor-cell interference by acquiring the channel information of the neighbor-cell terminals interfered by the transmitter and the scheduled terminal information during beamforming.

A method and apparatus for reducing crosstalk in a multi-channel communication system is disclosed. In one embodiment, outgoing signals in a multi-channel environment are manipulated into a transform domain, such as the frequency domain. Thereafter, the signals may be combined and modified based on a weighting variable to create a cancellation signal. Combined processing greatly reduces system complexity and increases processing speed. After processing in the transform domain, the cancellation signal undergoes further processing to return the cancellation signal into the time domain. The cancellation signal may then be combined with received signals to cancel crosstalk or echo. A method and apparatus for crosstalk cancellation in the analog domain and digital domain are also disclosed. Cancellation at least partially in the analog domain reduces the dynamic range requirements for digital to analog converters within the front-end processing system of a receiver and thereby reduces clipping and increases operating speed.

A directional notch filter for simultaneous transmit and receive of wideband signals comprises an antenna, an antenna match, a receiver, a power combiner, a first directional coupler, a second directional coupler and a shaping filter accepting a signal and producing a compensation signal as a replica of an antenna reflection transfer function, wherein the first and second directional couplers produce signals and portions of signals received by the antenna and sent to the receiver via the power combiner. The receiver can produce a receiver signal and the first directional coupler can produce a first signal as a portion of an overall signal received by the antenna, the first signal comprising at least reflection of a signal from the power amplifier and the second directional coupler samples a small portion of the receiver signal, said second directional coupler producing a second signal.

A system and method for providing cancellation of interference in a repeater configuration is disclosed, wherein the repeater is located between a first endpoint and a second endpoint. A data signal received from the first end point is amplified in accordance with an amount of power required to drive the data signal to the second endpoint. Local echo introduced by the repeater is then removed from the amplified data signal. Coupled signals introduced by the repeater are then removed after which the data signal is transmitted to the second endpoint.

An antenna array (10) for the transmission of signals (20) is disclosed. The antenna array (10) comprises: a plurality of transmission paths (30-1, 30-2, 30-K) for transmitting a plurality of wanted signals (25) and at least one calibration signal generator (40-1, 40-2,40-K) for the generation of at least one calibration signal (45). A plurality of calibration signal mixers (50-1, 50-2, 50-K) mixes the at least one calibration signal (45) with the plurality of wanted signals (25) to produce a plurality of transmission signals (20). A path sum signal device (60) sum the plurality of transmission signals (20) to produce a summed transmission signal (65); and an interference estimator (90) accepts the at least one calibration signal (45) and generates an estimated interference signal (92). An estimation signal mixer (95) subtracts from the summed transmission signal (65) the estimated interference signal (92) to produce a difference signal (97); and a on signal detection unit (70) for comparing the signal (97) with the at least one calibration signal (45).

Proposed is a user cooperative terminal device. The user cooperative device includes: a signal detector to receive a signal transmitted from a source node and detect a received signal; and a message generator to cancel interference caused by a neighboring user in the received signal, using a neighboring user message, and to generate a user message. The neighboring user may decode a received signal of the neighboring user to transfer the neighboring user message.