Abstract: A method and apparatus for using 802.11 Wireless LANs in TV white space are provided that additionally allows coexistence with non-802.11 devices in the same spectrum space. The method and apparatus extend concepts used in traditional 802.11 applications in the MAC and PHY layers so that WLANs can function over TV white space channels. The method and apparatus also facilitates coexistence of non 802.11 devices and existence with other 802.11 applications by extending the Enhanced Distributed Channel Access mechanism used to provide quality of service. An OFDM system with fixed subcarrier spacing is suggested to accommodate spectrum characteristics (variable center frequency and channel bandwidth) of the TVWS.

Abstract: A DMB-T receiver supports a single carrier (SC) form of modulation and a multi-carrier form of modulation such as orthogonal frequency division multiplexing (OFDM). Upon receiving a broadcast signal, the DMB-T receiver downconverts the received broadcast signal to a received base-band signal and determines a frame number for each frame by correlating groups of the received symbols in adjacent signal frames. In particular, the receiver determines a maximum right-shift correlation value and a maximum left-shift correlation value. If the magnitude of the maximum right-shift correlation value is greater than, or equal to, the magnitude of the maximum left-shift correlation value, then the maximum right shift correlation value is used to retrieve a frame number from a look-up table. Otherwise, the negative value of the maximum left-shift correlation value is used to retrieve a frame number from the look-up table.

Abstract: The invention relates to a wireless home gateway apparatus and methods of wirelessly delivering audio and/or video programs between a home gateway and a client device and to interference mitigation techniques on such system. Specifically, the invention relates to transmitting an audio video program on a first channel, receiving a control signal from a remote control indicating interference on said first channel, changing the transmission channel to a second channel, and transmitting data indicating said second channel to said remote control.

Abstract: A method and system for detection of available a white space channel in an area of licensed transmitters includes a detector which utilizes the autocorrelation analysis of a channel in an frequency modulated (FM) band. Calculation of the autocorrelation excludes an initial set of correlation delay values such that large values of autocorrelation are removed. The remaining autocorrelation based on higher correlation delay values exposes the sinusoidal nature of an FM transmitter operating in the selected channel. White space becomes available to a user if no transmitter is detected using the autocorrelation detection method.

Abstract: A Wireless Regional Area Network (WRAN) receiver comprises a transceiver for communicating with a wireless network over one of a number of channels, and an Advanced Television Systems Committee (ATSC) signal detector for use in forming a supported channel list comprising those ones of the number of channels upon which an ATSC signal was not detected. The ATSC signal detector comprises a matched filter that matches to at least a modulated version of an ATSC field sync signal for detecting the presence of an incumbent ATSC broadcast signal.

Abstract: Methods and apparatus for FEC frame header detection are provided, suitable for use in a DVB-C2 receiver. A first method comprises demodulating with a quadrature phase shift keying (QPSK) demapper, followed by correlation and symmetry measures for detection of a robust FEC header. A second method comprises demodulating with a 16 quadrature amplitude modulation (QAM) demapper, followed by correlation and symmetry measures for detection of a high efficiency FEC leader. Another embodiment comprises using both the first and second methods to find the FEC header because the first symbol of the FEC frame header may be sent either in robust mode or in high efficiency mode. There is also provided a method and apparatus for generating an alternate decision statistic for determining detection of the FEC frame header.

Abstract: Methods and apparatus for spectrum sensing for FM wireless microphone signals are provided. The spectrum sensing algorithm developed makes use of the property that the autocorrelation function of an FM signal is a sinusoidal function provided that the frequency) deviation is much smaller than the carrier frequency and the correlation delay is small. Based on this property, a simple spectrum sensing algorithm for the FM signal is designed by computing the autocorrelation function of the received signal and matched filtering of the sinusoidal function. The spectrum sensor provided by this approach can reliably detect the target signals when a strong adjacent channel interference exists and the signal power is as low as ?114 dBm.

Abstract: Methods and apparatuses for OFDM spectrum sensing are provided. The proposed spectrum sensing algorithms are based on Time-Domain Symbol Cross-Correlation (TDSC-MRC and TDSC-NP methods) and can be applied to all existing wireless OFDM systems. The statistical behaviors of the TDSC-based spectrum sensors are explicitly analyzed. In addition, the spectrum sensing method employing the Cyclic Prefix of the OFDM modulated signals (CP method) is described for comparison purposes. The DVB-T Standard is adopted as an application example to illustrate the proposed spectrum sensing algorithms. Simulation results show that the TDSC-MRC method outperforms the CP method for all values of CP ratio considered. The TDSC methods have the advantage that the detection performances are the same for different CP ratios, while the detection performance of the CP method degrades dramatically when the CP ratio becomes small.

Abstract: A frame header of Forward Error Correction (FEC) is provided, suitable for using in the DVB-C2 Standard. In the DVB-C2 Standard, Adaptive Coding and Modulation (ACM) or Variable Coding and Modulation (VCM) is applied to each FEC block to provide as much flexibility as possible. As a result, a frame header is attached in front of each FEC frame to inform the coding rate, modulation type and physical layer pipe identifier. Besides the signaling of physical layer related information, the FEC frame header has to provide a structure so that it can be easily and reliably detected in the receiver. Motivated by the need in DVB-C2 Standard, an efficient and reliable FEC header suitable for DVB-C2 Standard is provided in at least one implementation in this disclosure that combines use of two different modulation types for the header information. In addition, the detection Method of the FEC header is described.

Abstract: An efficient and reliable encoding method suitable for header information in a digital cable television transmission system is provided. An embodiment is shown for FEC frame headers in a DVB-C2 standard, along with the detection algorithm for the FEC header. In the DVB-C2 Standard, Adaptive Coding and Modulation (ACM) or Variable Coding and Modulation (VCM) is applied to each FEC block to provide as much flexibility as possible. As a result, a frame header is attached in front of each FEC frame to inform the coding rate, modulation type and physical layer pipe identifier. Besides the signaling of physical layer related information, the FEC frame header has to provide a structure so that it can be easily and reliably detected in the receiver. Motivated by the need in DVB-C2 Standard, an efficient and reliable method and apparatus to encode the FEC header for DVB-C2 Standard is provided in at least one implementation in this disclosure. In addition, the detection algorithm of the FEC header is described.

Abstract: This dissertation addresses the intersection of personal wireless technology and computational intelligence. The primary research issue addressed is the organization of radio domain knowledge into data structures processable in real-time that integrate machine learning and natural language processing technology into software radio. The thesis defines and develops the cognitive radio architecture. The features needed in the architecture are derived from cognitive radio use cases. These include inferring user communications context, shaping access-network demand, and realizing a protocol for real-time radio spectrum rental. Mathematical foundations for the knowledge-representation architecture are derived by applying point-set topology to the requirements of the use cases. This results in the set-theoretic ontology of radio knowledge defined in the Radio Knowledge Representation Language (RKRL). The mathematical analysis also demonstrates that isochronous radio software is not Turing-computable.

Abstract: A DMB-T receiver supports a single carrier (SC) form of modulation and a multi-carrier form of modulation such as orthogonal frequency division multiplexing (OFDM). Upon receiving a broadcast signal, the DMB-T receiver downconverts the received broadcast signal to a received base-band signal and determines a frame number for each frame by correlating groups of the received symbols in adjacent signal frames. In particular, the receiver determines a maximum right-shift correlation value and a maximum left-shift correlation value. If the magnitude of the maximum right-shift correlation value is greater than, or equal to, the magnitude of the maximum left-shift correlation value, then the maximum right shift correlation value is used to retrieve a frame number from a look-up table. Otherwise, the negative value of the maximum left-shift correlation value is used to retrieve a frame number from the look-up table.

Abstract: A DMB-T receiver supports a single carrier (SC) form of modulation and a multi-carrier form of modulation such as orthogonal frequency division multiplexing (OFDM). Upon receiving a broadcast signal, the DMB-T receiver downconverts the received broadcast signal to a received base-band signal and determines frame timing synchronization from the received signal as a function of frame header mode 1 and frame header mode 3 by correlating groups of received symbols spaced at least two signal frames apart within a sample shift value in a range of plus or minus one.

Abstract: An apparatus comprises a downconverter for providing a signal that may be a received orthogonal frequency division multiplexed (OFDM) symbols from a selected channel, each OFDM symbol comprising N subcarriers at least some of which are pilot subcarriers; and a processor that (a) correlates the received OFDM symbols for providing at least one correlated value, (b) generates a metric value as a function of the at least one correlated value and (b) compares the metric value to a threshold value for detecting if an incumbent signal is present.

Abstract: A Wireless Regional Area Network (WRAN) receiver comprises a transceiver for communicating with a wireless network over one of a number of channels, and a signal detector for use in forming a supported channel list comprising those ones of the number of channels upon which an Advanced Television Systems Committee (ATSC) DTV (digital television) broadcast signal was not detected. The signal detector performs spectrum sensing as a function of power spectral density (PSD) and cyclic spectrum.

Abstract: A Wireless Regional Area Network (WRAN) endpoint comprises a transceiver for communicating with a wireless network over one of a number of channels, and a DVB-T (Digital Video Broadcast-Terrestrial) signal detector for use in forming a supported channel list comprising those ones of the number of channels upon which a DVB-T signal was not detected. The WRAN endpoint processes a received signal to provide two data segments and determines an average of the autocorrelation of the two data segments at each one of eight transmission modes for the DVB-T signal. The WRAN endpoint then determines if a DVB-T signal is present as a function of the largest average autocorrelation value.

Abstract: A Wireless Regional Area Network (WRAN) receiver comprises a transceiver for communicating with a wireless network over one of a number of channels, and a signal detector for use in forming a supported channel list comprising those ones of the number of channels upon which an Advanced Television Systems Committee (ATSC) signal was not detected. The WRAN receiver performs a method comprising the steps of: dividing a total observation time looking for an ATSC data segment sync signal into multiple slices; computing at least one statistic for each slice; computing at least one overall statistic from the statistics computed for each slice; determining if the at least one overall statistic is greater than a threshold; and if the overall statistic is greater than the threshold, determining that an ATSC signal is present, otherwise, determining that an ATSC signal is not present.

Abstract: A Wireless Regional Area Network (WRAN) receiver comprises a transceiver for communicating with a wireless network over one of a number of channels, and an Advanced Television Systems Committee (ATSC) signal detector for use in forming a supported channel list comprising those ones of the number of channels upon which an ATSC signal was not detected. The ATSC signal detector comprises a matched filter that matches to at least a modulated version of an ATSC field sync signal for detecting the presence of an incumbent ATSC broadcast signal.

Abstract: A Wireless Regional Area Network (WRAN) receiver comprises a transceiver for communicating with a wireless network over one of a number of channels, and an Advanced Television Systems Committee (ATSC) signal detector for use in forming a supported channel list comprising those ones of the number of channels upon which an ATSC signal was not detected. The ATSC signal detector computes at least one cyclostationary feature of a received signal for determining if the received signal is an incumbent ATSC broadcast signal.

Abstract: A method of processing an OFDM signal to determine its FFT mode or the number of carriers without regard to the pilot pattern. The OFDM receiver determines autocorrelation functions corresponding to a plurality of possible FFT modes and variation-to-average ratios of these autocorrelation functions, respectively. The correct FFT mode is determined based on the variation-to-average ratios. In addition, a novel time and frequency synchronization scheme is performed after the correct FFT mode is detected.