Abstract: An interleaver of an OFDM/OFDMA transceiver reshapes a binary vector to be transmitted into a matrix, rotates bits in respective columns of the matrix, divides respective rows of the matrix into an integer number of interleaving blocks, and interleaves the bits in the respective interleaving blocks.

Abstract: The present invention provides a method for generating routing paths in a multi-hop network. The multi-hop network includes a base station, at least one relay station, and at least one non-relay mobile station. The routing paths are paths between the base station and the at least one non-relay mobile station via the at least one relay station. The base station broadcasts a path discovery message (PDM) including a path list with a starting point of the path list being the base station. Each of the relay stations receives the PDM and updates the PDM by adding their own respective node identifier to the path list and broadcasting the updated PDM. The PDMs eventually reach the non-relay mobile station. The non-relay mobile stations reply to the base station by sending the base station the updated path list between the base station and the non-relay mobile station.

Abstract: A radio frequency front end for a television band receiver and spectrum sensor includes a first plurality of adaptive matching networks connected to a signal summer that combines signals received by the first plurality of antennas respectively connected to the first plurality of adaptive matching networks and outputs a combined signal to each of a second plurality of downconverter/tuners. The downconverter/tuners are respectively or collectively connected to an analog to digital converter that converts output of the second plurality of downconverter/tuners into at least one digital signal that is output to the television band receiver and spectrum sensor.

Abstract: A received signal comprises a continuous sequence of symbols ?1, ?2, . . . ?n, each represented by a sequence of samples X0, X2, . . . Xn?1, and wherein the symbols have a guard period GP of duration Tgp at the beginning thereof. Each guard period contains a cyclic prefix with the same subsequence of samples as a tail end portion of the associated symbol. The symbols are identified by delaying the received signal by a fixed number of samples, computing the correlation of the received signal with the delayed signal, computing the summation of said correlation over a window of duration Ti, wherein Ti>Tgp, and sliding the window over the correlation to find a characteristic point or region. The start of each symbol for further processing is selected from the characteristic point or region. By increasing the duration of the window, more robust performance can be achieved, especially in multipath conditions.

Abstract: A television band device has DTV pilot signal detection logic that generates DTV pilot signal detection decisions associated with a monitored television channel. A wireless microphone detection logic generates wireless microphone detection decisions associated with the monitored television channel. A sensing manager receives DTV pilot signal detection decisions and the wireless microphone detection decisions and analyzes at least one the respective decisions to determine whether the monitored television channel is available white space.

Abstract: An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.

Abstract: A universal transmitter and a universal receiver for respectively transmitting and receiving orthogonal frequency-division multiplexing (OFDM) signals using the international television bands respectively use fixed subcarrier spacing; fixed Fast Fourier Transform (FFT)/Inverse Fast Fourier Transform (IFFT) period values; a fixed symbol duration for each cyclic prefix option; and fixed WRAN frame parameters, but a selectable channel bandwidth for transmission and reception.

Abstract: 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.

Abstract: A spectrum manager and base station controller for a wireless radio access network allocates TV band white space to all TV band devices under its control using: an allocation policy; information pulled/pushed from a white space database, spectrum usage data supplied by a spectrum sensing engine, and information received from at least one other peer spectrum manager and base station controller for the wireless radio access network.

Abstract: A system and method for proactive repeat transmission of data units sent using an unreliable transmission medium for the delivery of time sensitive data content predicts a future condition of a downlink data distribution channel using current channel estimation information. The predicted channel condition is used to determine which data units in a next data frame are likely to decode incorrectly, and a repeat transmission of those data units is explicitly requested by the receiving equipment, or automatically scheduled by the sending equipment using time domain channel state information provided to the sending equipment by the receiving equipment.

Abstract: An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.

Abstract: A wireless local area network (WLAN) gateway may use a modified LTE radio frame and TV white space spectrum for data communications in a wireless local area network. In the modified LTE downlink frame a predefined subset of the pilot (reference) symbol subcarriers are used to carry information to data sinks in the WLAN.

Abstract: Managing RF spectrum usage by secondary, or unlicensed, devices in portions of the RF spectrum where licensed, or primary, services operate is a requirement of cognitive radio systems. To perform the necessary spectrum scanning, a transition period, such as a TTG or RTG can be extended and the scanning performed during the extended period. The presence of a primary service signal can also detected by detecting an energy signature of the primary service signal in a known sequence. In both cases, there is no need to define quiet periods during which secondary devices scan the RF spectrum, thus resulting in saving of resources and improved QoS.

Abstract: Methods and systems for sharing white space with primary services and other emerging services are provided. Signal distribution within a specified location, such as a dwelling, is performed using a home gateway that identifies unused white space, reserves such white space spectrum, and delivers data to one or more devices at the respective location using the reserved spectrum. Signalling between the devices and the gateway is performed over a shared signalling channel, which enables the gateway to advise the devices from where and when to receive data. The gateway also uses a common spectrum reservation OFDM symbol to advise the neighbouring gateways of the local spectrum reservation.

Abstract: Wireless devices, transmitters, systems and methods are provided that have a narrow band signalling channel and a wide band channel, for example an OFDM channel. In order to save power, the wireless device is nominally powered down with the exception of a receiver specific to the narrow band signalling channel. Once instructed to do so over the narrow band signalling channel, the wireless device wakes up the rest of its wide band receive circuitry.

Abstract: Whitespace devices can use unused television frequencies for transmission and reception of WiFi OFDM signals. Three contiguous bands, such as former channels 2, 3, and 4, may be bonded together to define a whitespace band. In order to fit a WiFi OFDM signal into this whitespace band, a whitespace device compresses the bandwidth of each WiFi OFDM signal using a specific spectrum mask. Very low transmission power is needed for the modified WiFi OFDM signals, eliminating the need for high power amplifiers and most of the WiFi OFDM designs such as PHY and MAC can be reused with minor modifications.

Abstract: An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.

Abstract: Wireless devices, transmitters, systems and methods are provided that have a narrow band signalling channel and a wide band channel, for example an OFDM channel. In order to save power, the wireless device is nominally powered down with the exception of a receiver specific to the narrow band signalling channel. Once instructed to do so over the narrow band signalling channel, the wireless device wakes up the rest of its wide band receive circuitry.

Abstract: A wireless communication system comprises a wavelet analyzer and a wavelet signal generator. The wavelet analyzer is operable to analyze wireless signals within a frequency and time map of a communications spectrum, whereby the wavelet analyzer is adapted to determine one or more available cells within the frequency and time map. The wavelet signal generator is operable to generate one or more wavelet signals for transmission within the determined one or more available cells of the frequency and time map based on the analyzed wireless signals within the frequency and time map.

Abstract: Redistribution of multimedia signals or the like within a service area is performed by identifying one or more pieces of white space in the VHF/UHF spectrum, selecting a carrier frequency for each piece of white space spectrum, parsing the signal into a like number of components and modulating each component over a carrier frequency. The receiving device performs the reverse operation for reconstructing the signal.