52results about "Depolarization effect reduction" patented technology

In a MIMO system using a cross-polarized antenna structure, even if no ideal XPD can be obtained, the interference between different polarized waves can be reduced to allow an effective precoding to be executed. When a MIMO communication is performed between a transmitter (250) and a receiver (260) each using a cross-polarized antenna structure, a channel estimating and precoding selection section (214) of the receiver (260) performs a channel estimation of MIMO channels from the transmitter to the receiver, decides a precoding matrix (P) of a projection matrix for mutually orthogonalizing or substantially orthogonalizing the channel response matrixes for respective different polarized waves, and feeds the determined precoding matrix (P) back to the transmitter (250). In the transmitter (250), a precoding processing section (208) applies the precoding matrix (P) to the spatial stream corresponding to one of the polarized waves to perform a precoding, thereby allowing the transmitter (250) to transmit the polarized waves with the orthogonality therebetween maintained.

An apparatus and method for interference cancellation in wireless mobile stations operating concurrently in two or more wireless modes.

An orthogonal cross-polarization interference compensating device for solving the problem tin which integration contents of an integration circuit are indefinite when a control loop is cut. An orthogonal cross-polarization interference compensator generates a compensation signal for compensating phase noise included in an own polarization signal. A demodulator compensates for orthogonal cross-polarization interference based on the compensation signal for the phase noise included in the own polarization signal. An error detector generates an error signal indicating phase difference between the own polarization signal compensated by the demodulator and a proper own polarization signal. A phase noise phase detector generates a differential signal indicating phase difference between the own polarization signal and other polarization signals based on the compensation signal and the error signal. An integration circuit integrates the differential signal and generates an integration signal. An infinite phase-shifter adjusts the compensation signal based on the integration signal. A control circuit determines whether or not orthogonal cross-polarization interference is present based on the compensation signal adjusted by the infinite phase-shifter, and adjusts the integration value indicated by the integration signal to be a predetermined value when there is no orthogonal cross-polarization interference.

A cross polarization interference canceling apparatus of the present invention includes: error detector 26 for extracting a difference between a demodulated signal that is the main polarization signal in which compensation for cross polarization interference has been made and the received signal which indicates an ideal state of the main polarization, and outputting an error signal that indicates the extracted difference; phase noise detector 27 for outputting a phase noise difference by comparing a cross polarization interference compensating signal that is the opposite polarization signal in which compensation for cross polarization interference has been made with the error signal; a control signal generator for generating a control signal corresponding to the phase noise difference; and phase rotator 18′ disposed prior to, or posterior to, a cross polarization interference canceller for generating the cross polarization interference compensating signal, for controlling the phase of the cross polarization interference compensating signal in such a direction as to suppress the phase noise difference, in response to the input of the control signal.

[Object]A wireless communication system capable of detecting propagation path modification from the outside and compensating for degradation of quality of communication between transmission and reception with respect to the propagation path modification is provided. A wireless communication system includes a transmitter that transmits electromagnetic waves in which a polarization direction rotates according to a signal in which data is loaded on a carrier, and a receiver that receives the electromagnetic waves and demodulates the data, in which the transmitter imparts angle information indicating a polarization direction for transferring the data to the signal, and sets a rotation frequency of the polarization direction to a frequency lower than a frequency of the carrier, and the receiver changes a polarization direction of the received electromagnetic waves, based on the angle information transferred by the electromagnetic waves. The receiver can detect propagation path modification from the outside using the angle information of the polarization direction, and compensate for degradation in quality of communication between transmission and reception by changing the polarization direction of the received electromagnetic waves when the modification is detected.

A method is provided for generating precoder data (600), comprising: obtaining transmit power data indicative of a transmit power of a plurality of multiple-input / multiple-output signals (610); obtaining signal quality data, the signal quality data including at least one measure of a quality of the plurality of multiple-input / multiple-output signals (620, 630); obtaining channel data with respect to a wireless channel, the channel data including a measure of respective channel parameters of each of a plurality of channel paths in the wireless channel (620, 630); constraining one or more system performance parameters (640); and determining first and second precoder diagonal values (wA and wB) based on the signal quality data, the transmit power data, the channel data, and the one or more constrained system performance parameters (650).

Cross-polar discrimination (XPD) of a dual orthogonal cross-polarised antenna is maximized via a cross-coupling network between base station MIMO branches prior to connection to the base station antenna. In one embodiment, a cross coupling network combines each MIMO branch signal with an attenuated phase reversed (phase shifted) copy of the other MIMO branch signal. The amount of attenuation for each branch is equivalent to the cross polar suppression required for each antenna array. The cross-coupling can be applied at different stages of signal processing within a base station.

An apparatus and method for interference cancellation in wireless mobile stations operating concurrently in two or more wireless modes.

An exemplary system may comprise a first and second device and a first and second power splitter coupled to a single cable. The first device may be configured to receive a first noise signal of a first polarization, and to adaptively cancel, based on the first noise signal, first noise from the noisy signal associated with an orthogonal polarization. The second device may be configured to receive a second noise signal of a second polarization, and to adaptively cancel second noise from the noisy signal associated with an orthogonal polarization based on the second noise signal. The first power splitter may be configured to receive the first noise signal from the single cable and provide the first noise signal to the first device. The second power splitter may be configured to receive the second noise signal from the single cable and provide the second noise signal to the second device.

Cross polarization interference can be compensated even in the case that dual polarization transmitters of opposing station devices output different signals. A cross polarization interference compensation device is provided with a main signal reception unit which receives a signal having a first polarization direction; an interference signal reception unit which receives a signal having a second polarization direction which intersects the first polarization direction; a phase control unit which controls a phase of the interference signal; an interference compensation signal generation unit which generates an interference compensation signal by chronological weighted synthesis of the signal output from the phase control unit, and sets a weighting coefficient used in the weighted synthesis so that the interference compensation signal becomes a cross polarization interference component of the main signal; a phase estimation unit which estimates a phase difference between the main signal and the interference signal using information relating to the weighting coefficient; and a compensation unit which compensates the cross polarization interference using the interference compensation signal; wherein the phase control unit controls the phase of the interference signal using the phase difference estimated by the phase estimation unit so that the phase of the main signal matches the phase of the interference signal.

An antenna system for receiving an RF signal from a first antenna and a second antenna includes a phase shift circuit. The phase shift circuit shifts a phase of the RF signal from the second antenna by one of a plurality of possible phase shifts to produce a phase shifted signal. A combiner combines the RF signal from the first antenna and the phase shifted signal to produce a combined signal. A comparator circuit compares a signal quality of the combined signal with a minimum threshold value to determine if the signal quality of the combined signal is equal to or greater than the threshold value. The comparator circuit is in communicative control of the phase shift circuit and maintains the phase shift of the RF signal received by the second antenna in response to the signal quality of the combined signal being equal to or greater than the threshold value.

A cross polarization interference canceling apparatus of the present invention includes: error detector 26 for extracting a difference between a demodulated signal that is the main polarization signal in which compensation for cross polarization interference has been made and the received signal which indicates an ideal state of the main polarization, and outputting an error signal that indicates the extracted difference; phase noise detector 27 for outputting a phase noise difference by comparing a cross polarization interference compensating signal that is the opposite polarization signal in which compensation for cross polarization interference has been made with the error signal; a control signal generator for generating a control signal corresponding to the phase noise difference; and phase rotator 18′ disposed prior to, or posterior to, a cross polarization interference canceller for generating the cross polarization interference compensating signal, for controlling the phase of the cross polarization interference compensating signal in such a direction as to suppress the phase noise difference, in response to the input of the control signal.

The embodiment of the invention provides a channel state information feedback method. The method comprises: receiving downlink symbols from a base station, wherein the downlink symbols comprise pilot frequency; obtaining a channel matrix according to the pilot frequency included in the downlink symbols; calculating a precoding matrix according to the channel matrix and a basic codebook; generating a CSI according to the precoding matrix; and sending uplink symbols to the base station, wherein the uplink symbols carry CSI. The embodiment of the invention further provides a precoding method, a terminal device and a base station. According to the technical scheme provided by the invention, each group of antennas selects at least one wave beam for weighting merging to construct a new wave beam, and the new wave beam is used to perform weighting of the group of antennas. The constructed network wave beam can more accurately simulate the real environment of the channel so as to improve the precoding accuracy.

A method and device for compensation of received signal components at a user equipment (UE) used for receiving signal components from a radio base station (RBS). The signal components have at least a first and a second polarization orientation, respectively. The intended reception of the signal component (Yh(n)) having the first polarization deviates from the polarization orientation of the transmitted signal component (Xh(n)) having the first polarization by a first angle (φ), and the intended reception of the signal component (Yv(n)) having the second polarization deviates from the polarization orientation of the transmitted signal component (xv(n)) having the second polarization by a second angle (θ). The method comprises the steps: determining the correlation values (Ryvv, Ryvy, Ryyv, Ryyy) for the received signals (Yh, Yv) at a first time (k) and a second time (m); using these values to determine the deviation angles (φ, θ) performing said compensation using the deviation angles (φ, θ).

An analog beamforming transmitter includes: a plurality of beamforming transmission circuits coupled in parallel between a signal input and an array of antenna ports, wherein the signal input is configured to receive an analog complex-valued communication signal having an in-phase and a quadrature component, wherein each antenna port of the array of antenna ports is configured to provide a dual-polarized antenna signal having a first polarization component and a second polarization component, wherein each beamforming transmission circuit is coupled between the signal input and a respective antenna port of the array of antenna ports, wherein each beamforming transmission circuit comprises a first coefficient input for receiving a first analog complex-valued beamforming coefficient a set offirst analog complex-valued beamforming coefficients and a second coefficient input for receiving a second analog complex-valued beamforming coefficient of a set of second analog complex-valued beamforming coefficients.

Cross-polar discrimination (XPD) of a dual orthogonal cross-polarized antenna is maximized via a cross-coupling network between base station MIMO branches prior to connection to the base station antenna. In one embodiment, a cross coupling network combines each MIMO branch signal with an attenuated phase reversed (phase shifted) copy of the other MIMO branch signal. The amount of attenuation for each branch is equivalent to the cross polar suppression required for each antenna array. The cross-coupling can be applied at different stages of signal processing within a base station.

An antenna system and method utilize a splitter electrically connectable to a single antenna for splitting an RF signal into two signals. A variable phase shifter shifts the phase of one of the signals. A combiner combines the phase shifted and non-phase shifted signals to produce a conditioned signal. A quality examiner circuit changes the amount of phase shift provided by the variable phase shifter to produce a plurality of different conditioned signals. The quality examiner circuit then determines a quality of each conditioned signal and changes the phase shift again to provide the highest quality conditioned signal to a receiver.

Embodiments of the present invention disclose a co-channel dual polarized microwave device and a method. Frame synchronization is performed on a first receive signal processed by cross polarization interference cancellation and phase noise immunization is performed on the first receive signal processed by frame synchronization. Frame synchronization is performed on a second receive signal not processed by cross polarization interference cancellation and phase noise immunization is performed on the second receive signal processed by frame synchronization. The first receive signal processed by phase noise immunization and the second receive signal processed by phase noise immunization are selectively received according to a frame synchronization state signal and a signal quality signal. Delay alignment is performed on a selectively received signal according to the frame synchronization state signal to implement lossless switching in a selective receiving process.

Certain aspects of the present disclosure relate to methods and apparatus for wireless communication. More particularly, aspects of the present disclosure generally relate to techniques for wireless communications by a first apparatus comprising a first interface for obtaining, via at least one receive antenna, first and second training signals transmitted from a second apparatus via at least first and second transmit antennas having different polarizations, and a processing system configured to determine, based on the first and second training signals, one or more characteristics for different transmit-receive antenna pairs, each pair comprising one of the first and second transmit antennas and the at least one receive antenna, and generate, based on the one or more characteristics, a parameter indicative of a rotation of the first apparatus relative to the second apparatus.

[Object]A wireless communication system capable of detecting propagation path modification from the outside and compensating for degradation of quality of communication between transmission and reception with respect to the propagation path modification is provided. A wireless communication system includes a transmitter that transmits electromagnetic waves in which a polarization direction rotates according to a signal in which data is loaded on a carrier, and a receiver that receives the electromagnetic waves and demodulates the data, in which the transmitter imparts angle information indicating a polarization direction for transferring the data to the signal, and sets a rotation frequency of the polarization direction to a frequency lower than a frequency of the carrier, and the receiver changes a polarization direction of the received electromagnetic waves, based on the angle information transferred by the electromagnetic waves. The receiver can detect propagation path modification from the outside using the angle information of the polarization direction, and compensate for degradation in quality of communication between transmission and reception by changing the polarization direction of the received electromagnetic waves when the modification is detected.

A method and device for compensation of received signal components at a user equipment (UE) used for receiving signal components from a radio base station (RBS). The signal components have at least a first and a second polarization orientation, respectively. The intended reception of the signal component (Yh(n)) having the first polarization deviates from the polarization orientation of the transmitted signal component (Xh(n)) having the first polarization by a first angle (φ), and the intended reception of the signal component (Yv(n)) having the second polarization deviates from the polarization orientation of the transmitted signal component (xv(n)) having the second polarization by a second angle (β). The method comprises the steps: determining the correlation values (Ryw, Ryvy, Ryyv, Ryyy) for the received signals (Yh, Yv) at a first time (k) and a second time (m); using these values to determine the deviation angles (φ, θ) performing said compensation using the deviation angles (φ, θ).

A method is provided for generating precoder data (600), comprising: obtaining transmit power data indicative of a transmit power of a plurality of multiple-input / multiple-output signals (610); obtaining signal quality data, the signal quality data including at least one measure of a quality of the plurality of multiple-input / multiple-output signals (620, 630); obtaining channel data with respect to a wireless channel, the channel data including a measure of respective channel parameters of each of a plurality of channel paths in the wireless channel (620, 630); constraining one or more system performance parameters (640); and determining first and second precoder diagonal values (wA and wB) based on the signal quality data, the transmit power data, the channel data, and the one or more constrained system performance parameters (650).

Disclosed is a Doppler frequency detector for detecting a Doppler frequency of a received signal. The detector includes a channel estimating unit, a channel phase variation amount calculating unit, a Doppler frequency estimating unit and a calculation interval calculating unit. The channel estimating unit calculates a channel estimate based on a pilot signal in the received signal. The channel phase variation amount calculating unit calculates channel phase variation amount based on the channel estimate and a calculation interval. The Doppler frequency estimating unit estimates the Doppler frequency based on the channel phase variation amount and outputs a Doppler frequency estimate. The calculation interval calculating unit calculates the calculation interval based on the Doppler frequency estimate and supplies the calculated calculation interval to the channel phase variation amount calculating unit.

The invention provides a method and a device for testing the XPIC performance of microwave transmission equipment, relates to the technical field of communication, and aims at effectively testing theXPIC performance of the microwave transmission equipment, the testing device is simple, and the testing result is safe and reliable. The device comprises: a transmitting device and a receiving deviceto be tested, which are used for transmitting and receiving microwave signals; a pass-type polarization degradation plate which is arranged between the transmitting device and the receiving device andis used for carrying out degradation separation on the electromagnetic waves to separate the electromagnetic waves into two electromagnetic wave signals with different polarization directions; a network performance analyzer V which is used for measuring the receiving power of the receiving device in the vertical polarization direction, wherein the network performance analyzer H is used for measuring the receiving power of the receiving device in the horizontal polarization direction, and the polarization coupling interference ratio is calculated according to the measured receiving power and is used for analyzing the XPIC performance of the microwave transmission equipment. The technical scheme provided by the invention is suitable for the XPIC performance test process of the microwave transmission equipment.

The present invention discloses a dual polarization microwave device in the same channel and a receiving method for receiving the receipt signal, being characterized by: performing frame synchronization processing to the first receipt signal after the cross polarization interference cancellation; performing phase noise immunization processing to the first receipt signal after frame synchronization processing; performing frame synchronization processing to the second receipt signal which is not processed by the cross polarization interference cancellation; performing the phase noise immunization processing to the second receipt signal after the frame synchronization processing; selectively receiving the first receipt signal and the second receipt signal after the phase noise immunization processing according to the frame synchronization state signal and teh signal quality signal; performing delay alignment for the selectively received signals according to the frame synchronization state signal so as to realize the lossless switching of the selectively receiving process. If a microwave device failure causes a cross polarization interference cancellation error, the microwave device selectively receives the receipt signal which is not processed by the cross polarization interference cancellation and performs the delay alignment processing so as to realize the lossless switching of the selectively receiving process.

A first signal having a first polarization direction and a second signal having a second polarization direction crossing the first polarization direction are received. A phase of the second signal is controlled using a phase control signal. An interference compensation signal is generated by weighted combination on a time-series of a signal whose phase has been controlled. Weighting coefficients used for the weighted combination are set so that the interference compensation signal becomes a cross-polarization interference component of the first signal. A phase difference between the first signal and the second signal is estimated using the weighting coefficients. The phase control signal is generated using the estimated phase difference so that a phase of the first signal and the phase of the second signal become identical. The first signal is compensated for cross-polarization interference caused by the second signal using the interference compensation signal and the first signal.

A wireless device includes a first antenna and a second antenna that may be used to communicate with a wireless network. The wireless device initiates a traffic call with a wireless network and activates a first antenna to be used to communicate with the wireless network upon initiating the traffic call. The wireless device selectively activates a second antenna, when initiating the traffic call, based at least in part on a usage of the second antenna during a previous traffic call. For example, the wireless device may maintain the second antenna in an inactive state if the second antenna was deactivated during the previous traffic call and / or remained inactive for at least a threshold duration.

In order to improve the efficiency of removing a component of a signal different from a target received signal, a transmission apparatus includes: a reception means for receiving a first signal transmitted by a first transmission apparatus, and removing a component of a second signal transmitted by a second transmission apparatus, the second signal being received along with the first signal, using a third signal inputted from a third transmission apparatus receiving the second signal; a control means for setting a first modulation method based on the first signal, and generating first information, the first information being information including directions to change a modulation method of the first signal and a modulation method of the second signal to the first modulation method; and a transmission means for transmitting the first information to the first transmission apparatus.