1089results about "Spectral gaps assessment" patented technology

A transmitter comprises a local oscillator circuit operable to generate a reference signal, a modulator circuit operable to generate a data-carrying signal using the reference signal, and a test signal generator circuit operable to generate a test signal using the reference signal. The test signal has a first bandwidth, and a test signal insertion circuit is operable to combine the data-carrying signal and the test signal to generate a combined signal. An amount of bandwidth in the combined signal allocated to the test signal is greater than the first bandwidth such that a component of the combined signal corresponding to the test signal is bordered by whitespace. A receiver may then use the test signal to determine and correct for phase noise introduced in the transmitter.

Methods and systems for dynamic spectrum access (DSA) in a wireless network are provided. A DSA-enabled device may sense spectrum use in a region and, based on the detected spectrum use, select one or more communication channels for use. The devices also may detect one or more other DSA-enabled devices with which they can form DSA networks. A DSA network may monitor spectrum use by cooperative and non-cooperative devices, to dynamically select one or more channels to use for communication while avoiding or reducing interference with other devices.

Channel Optimization in Half Duplex Communications Systems is provided herein. Methods may include obtaining at a first terminal, radio frequency (RF) spectral information local to the first terminal, analyzing at the first terminal, RF spectral information for a second terminal that is not co-located with the first terminal, transmitting data to the second terminal on a second terminal optimal frequency band, and receiving data from the second terminal on the first terminal optimal frequency band, where the first terminal optimal frequency being based upon the RF spectral information local to the first terminal.

The embodiment of the invention provides a method and base station for transmitting and receiving signals by using unauthorized carrier waves and user equipment. The method includes the steps that the base station transmits unauthorized carrier wave information to the user equipment (UE) through authorized carrier waves; after obtaining the use right to the unauthorized carrier waves through competition in a competition backspacing window, the base station uses residual resources and / or subframes behind the residual resources in the competition backspacing window for transmitting the signals to the UE, and the residual resources comprise complete orthogonal frequency-division multiplexing (OFDM) symbols after the moment point of obtaining the use right of the unauthorized carrier waves through competition and located in the competition backspacing window, or complete PFDM symbols between the moment point of obtaining the use right of the unauthorized carrier waves for the base station through competition and the moment when the subframe where the moment point is located is finished.

TV white space spectrum sensors and methods for detecting and managing the white space are provided. The sensor is provided with a spectrum detector / analyzer, which senses and analizes the wireless signals present in a spectrum of interest, identifies white space, and assigns the white space to secondary services. For reducing the white space detection time, the sensor uses a group detection method whereby multiple channels are sensed simultaneously. For reducing the sensor cost, the dynamic range of the sensor is reduced by operating the sensor in saturation for signals with the energy higher than a threshold. The sensor is also provided with a spectrum manager / planner capable of understanding a plurality of air interface standards, reserving and providing the right amount of white space spectrum to each application, based on the respective standard requirements. The particular architectures used by the sensor result in an affordable addition to any wireless device.

A first storage stores a first number of streams which are capable of being demultiplexed by the wireless communication apparatus. A first acquisition unit acquires a second number of streams which are capable of being demultiplexed by a first wireless communication apparatus. A second acquisition unit acquires a third number of sum of streams of communications performed by the wireless communication apparatus and the first wireless communication apparatus. A second storage stores, if the first number of streams exceeds the third number of streams, a difference between the first and third numbers of streams as an allowable number of streams. A determination unit determines that a wireless medium is idle, in the case where a number of streams required for perform a new communication is not more than the allowable number of streams.

Described herein are methods to enable wireless cellular operation in unlicensed and lightly licensed, (collectively referred to as license exempt spectrum. Cognitive methods are used to enable use of unlicensed bands and / or secondary use of lightly licensed bands. Wireless devices may use licensed exempt spectrum as new bands in addition to the existing bands to transmit to a wireless transmit / receive unit (WTRU) in the downlink direction, or to a base station in the uplink direction. The wireless devices may access license exempt spectrum for bandwidth aggregation or relaying using a carrier aggregation framework. In particular, a primary component carrier operating in a licensed spectrum is used for control and connection establishment and a second component carrier operating in a licensed exempt spectrum is used for bandwidth extension.

A technique for a secondary communication system to utilize spectrum designated to another (or primary) communication system is provided. By ranking a plurality of secondary base stations based on base station transmit power, calculated required transmit power and path loss, a set of criteria is developed for selecting a highest ranked secondary base station for operation within a primary's spectrum. The ranking may be adapted based on mobility of the secondary's subscriber; and as such the secondary system communicates within the primary's spectrum using the adaptively ranked base stations. Channel selection may also be ranked. The technique and apparatus allows a cognitive radio (CR) network to operate within an incumbent network's spectrum.

Methods and systems for dynamic spectrum access (DSA) in a wireless network are provided. A DSA-enabled device may sense spectrum use in a region and, based on the detected spectrum use, select one or more communication channels for use. The devices also may detect one or more other DSA-enabled devices with which they can form DSA networks. A DSA network may monitor spectrum use by cooperative and non-cooperative devices, to dynamically select one or more channels to use for communication while avoiding or reducing interference with other devices.

A wireless transceiver comprising: a receiver adapted to receive signals in a television broadcast band; and a transmitter adapted to transmit signals in a different band. Also provided is a counterpart transceiver. The latter transceiver comprises: a transmitter adapted to transmit signals in a television broadcast band; and a receiver adapted to receive signals in the different band.

Techniques are described for wireless communication. A first method includes generating uplink control information at a wireless device, and transmitting the uplink control information over an interlace of a component carrier of an unlicensed radio frequency spectrum band. The interlace includes a plurality of non-contiguous concurrent resource blocks in the unlicensed radio frequency spectrum band, and at least two resource blocks in the interlace include different portions of the uplink control information. A second method includes generating uplink control information at a wireless device, and transmitting the uplink control information over an uplink control channel of an unlicensed radio frequency spectrum band. Resources of the uplink control channel are divided into a plurality of discrete dimensions and the uplink control information of the wireless device is transmitted over a number of the discrete dimensions allocated to the uplink control information of the wireless device.

The invention provides a channel detection notification method, a channel detection notification system and base stations used when an LTE system works at an unauthorized frequency band. The channel detection notification method includes the steps that the primary cell base station receives RRM measuring results, reported by a terminal, of multiple base stations at the unauthorized frequency band; according to the RRM measuring results of the base stations, the secondary cell base station is selected for the terminal; if it is determined that downlink traffic reaches a set first traffic threshold value, the secondary cell base station is informed to conduct downlink channel detection; if it is determined that uplink traffic reaches a set second traffic threshold value, the secondary cell base station and / or the terminal are / is informed to conduct uplink channel detection. According to the channel detection notification method, channel detection work conducted when the LTE system works at the unauthorized frequency band is managed by the primary cell base station in a united mode, the time delay generated when the secondary cell base station and / or the terminal carry / carries out channel detection can be effectively shortened, accuracy at which channel detection time is judged can be improved, and the resource utilization rate is increased when the LTE system works at the unauthorized frequency band.

Embodiments include processes, systems, and devices for reshaping virtual baseband signals for transmission on non-contiguous and variable portions of a physical baseband, such as a white space frequency band. In the transmission path, a spectrum virtualization layer maps a plurality of frequency components derived from a transmission symbol produced by a physical layer protocol to sub-carriers of the allocated physical frequency band. The spectrum virtualization layer then outputs a time-domain signal derived from the mapped frequency components. In the receive path, a time-domain signal received on the physical baseband is reshaped by the virtual spectrum layer in order to recompose a time-domain symbol in the virtual baseband.

A broadband local area data network uses coaxial cable wiring for interconnection of terminal devices. Orthogonal frequency division multiplexing (OFDM) with bit loading is used to overcome channel impairments and provide a path for terminal devices to transmit to and receive from other terminal devices. Probe messages are sent between devices to characterize the communication channel and determine optimum bit loading. The data network shares the cable spectrum with other services and uses frequency bands not used by other services. Adaptive power control can be used to maintain signal to noise ratio in a communication between terminal devices. Frequency coordination can be used to avoid interference between the LAN communications and other services transmitted on the cable.

A signaling method between a cognitive radio (CR) base station and a CR terminal in a CR environment, and a channel division method used for the signaling method, includes: detecting a channel usage of an incumbent system, which communicates with a CR base station; sensing an outband channel to communicate with the CR base station; receiving an EOS, which is broadcasted from the CR base station via the outband channel according to a predetermined period; and transmitting a sensing report signal with respect to the channel to the CR base station.

Provided is a radio communication method which can reduce the power consumption as compared to the conventional technique while realizing coexistence of a plurality of radio communication methods and can perform synchronization with a super frame of other radio communication device. The super frame has life confirmation slots (2820, 2830) through which radio communication devices of various modulation types should transmit tone signals. A radio communication device has a chance to judge whether one or more radio communication devices using a different modulation type exist or no such device exists in the vicinity. If no such device exists, the slot to be used by the radio communication device of the modulation method is reported as a time that can be used by a radio communication group of other modulation method. Thus, by confirming existence of an object in the vicinity by other radio communication device with which communication cannot be performed, communication can be performed by sharing the super frame.

A wireless mesh communication network includes a plurality of wireless routers which can be managed in a hierarchical manner with respect to one another and all of the routers are capable of detecting and avoiding interference on channels over which they communicate with one another. Depending upon whether a channel is active or inactive, a wireless router can either passively detect interference and then switch channels to avoid it or actively detect interference and then switch channels to avoid it.

A system and method for synchronous spectrum sharing for use in a wireless communication system based on orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) signaling is disclosed. The system includes a frame detector configured to detect a frame of a broadcast waveform and extract idle spectrum information for the frame to the secondary user node. The system allows transmitting data from the secondary user node in unused symbol slots identified in the idle spectrum information thereby making efficient use of unused or idle spectrum. Accordingly, secondary users of the wireless communication system can dynamically form ad-hoc mesh network communications in fixed or mobile scenarios.

A communication system is presented, which is capable of sending a transmission over an interface having at least two aggregated component carriers including a primary component carrier and at least one secondary component carrier, wherein the primary component carrier has a physical downlink control channel (PDCCH) associated therewith and wherein the PDCCH is capable of signaling allocations for the primary component carrier and the at least one secondary component carrier. A method of operating a network element including sending to a user equipment a transmission indication indicative of the transmission in the PDCCH of the primary component carrier. A method of operating a user equipment includes monitoring downlink control signaling for a transmission indication indicative of a transmission to the user equipment only on the PDCCH of the primary component carrier.

A system, method, and computer-readable medium for detection and avoidance of victim services in ultra-wideband systems is provided. A detect and avoid module may calculate power averages of OFDM tones. The power of tones may then be measured and compared with power averages of corresponding tones. If a measured tone power exceeds an average power of a corresponding tone by a dynamic threshold, the tone may be identified as associated with an interferer. The threshold may be inversely related to the gain level of an automatic gain control module. The ultra-wideband subsystem may be configured with known bands of victim services of other RF systems, and a tone identified as associated with an interferer that is within a known victim service band may be identified as a victim service. The UWB subsystem may attenuate or otherwise suppress transmission within the victim service band to avoid interfering with the victim service.

A method and transceiver for wireless multicarrier communications. At the transmitter side, conventional OFDM symbols, after inverse fast Fourier Transform, are scrambled in time domain and then guard-interval (GI) inserted, up-converted at the carrier frequency for transmission. At the receiver side, after GI removal and frequency domain channel equalization, the received signal is transformed into time-domain by inverse fast Fourier Transform. The time-domain equalized signal is descrambled in time domain and then transformed back to the frequency domain before it is rate-matched, demodulated and decoded. This time-domain scrambling and descrambling method can be used in a wireless OFDM system such as WLAN, cellular OFDM, and MC-CDMA.

A method detects unused frequency bands in a cognitive radio network. Multiple frequency bands for RF signals are sensed using an antenna array including a plurality of elements coupled to a receive RF chain, in which the plurality of elements are individually controllable. For each frequency band, multiple spatial directions are sensed for the RF signals using the antenna array. A particular frequency band and a particular direction and a particular time slot are assigned as an available frequency band, an available direction and a particular time slot for transmitting RF signals in a cognitive radio if the RF signals are not sensed in the particular spatial direction for the particular frequency band, and in which the RF signals are transmitted by a transmit chain connected to the antenna array.

This disclosure relates to Wi-Fi signaling in conjunction with cellular communication in unlicensed frequency bands for efficient co-existence. According to one embodiment, a cell may be established between a cellular base station and a wireless user equipment device on a frequency channel in an unlicensed frequency band. A cellular communication may be scheduled between the base station and the user equipment device. A Wi-Fi signal may be transmitted on the frequency channel in conjunction with the scheduled cellular communication. The Wi-Fi signal may indicate a length of the scheduled cellular communication using Wi-Fi signaling. The scheduled cellular communication may be performed via the cell.

The present invention is a computationally-efficient compensator for removing nonlinear distortion. The compensator operates in a digital post-compensation configuration for linearization of devices or systems such as analog-to-digital converters and RF receiver electronics. The compensator also operates in a digital pre-compensation configuration for linearization of devices or systems such as digital-to-analog converters, RF power amplifiers, and RF transmitter electronics. The compensator effectively removes nonlinear distortion in these systems in a computationally efficient hardware or software implementation by using one or more factored multi-rate Volterra filters. Volterra filters are efficiently factored into parallel FIR filters and only the filters with energy above a prescribed threshold are actually implemented, which significantly reduces the complexity while still providing accurate results. For extremely wideband applications, the multi-rate Volterra filters are implemented in a demultiplexed polyphase configuration which performs the filtering in parallel at a significantly reduced data rate. The compensator is calibrated with an algorithm that iteratively subtracts an error signal to converge to an effective compensation signal. The algorithm is repeated for a multiplicity of calibration signals, and the results are used with harmonic probing to accurately estimate the Volterra filter kernels. The compensator improves linearization processing performance while significantly reducing the computational complexity compared to a traditional nonlinear compensator.

Provided is a method for sensing a channel of a whitespace band in a wireless LAN system. A method for sensing and reporting a channel of a whitespace band in a wireless LAN system according to one embodiment of the present invention comprises the steps of: receiving a sensing request including a candidate report channel and a target channel of a whitespace band to be sensed; sensing the target channel; and determining a channel for transmitting sensed results in accordance with whether a licensed user is detected on the target channel, and transmitting the sensed results.

Apparatus and methods for identifying a wireless signal-emitting device are disclosed. The apparatus is configured to sense and measure wireless communication signals from signal-emitting devices in a spectrum. The apparatus is operable to automatically detect a signal of interest from the wireless signal-emitting device and create a signal profile of the signal of interest; compare the signal profile with stored device signal profiles for identification of the wireless signal-emitting device; and calculate signal degradation data for the signal of interest based on information associated with the signal of interest in a static database including noise figure parameters of a wireless signal-emitting device outputting the signal of interest. The signal profile of the signal of interest, profile comparison result, and signal degradation data are stored in the apparatus.

Methods and apparatuses are described in which an unlicensed spectrum is used for Long Term Evolution (LTE) communications. A first method includes broadcasting beacon signals in an unlicensed spectrum at predetermined times from an evolved Node B (eNB). A second method includes receiving beacon signals broadcast in an unlicensed spectrum at predetermined times from an eNB. The beacon signals may include downlink signals identifying the eNB and at least one associated attribute of the eNB.

Techniques are described for wireless communication. A first method includes receiving from a base station an indication of a set of one or more uplink interlaces of an unlicensed radio frequency spectrum band allocated for a sounding reference signal, and transmitting the sounding reference signal for a user equipment (UE) over the indicated set of one or more uplink interlaces of the unlicensed radio frequency spectrum band. A second method includes receiving an indication of an interlace of an unlicensed radio frequency spectrum band allocated for a physical uplink control channel (PUCCH) transmission, and transmitting a scheduling request and a buffer status report over the indicated interlace.

Disclosed herein are a method and apparatus for sending and receiving data in a wireless communication system. More specifically, a method for sending and receiving, by UE, data in an unlicensed band in a wireless communication system may include performing blind detection for detecting a predetermined specific signal transmitted by an eNB in a cell of an unlicensed band and determining a period in which the signal is detected through the blind detection to be a reserved resource period (RRP) which is a time period secured for the transmission and reception of data in the cell of the unlicensed band.