Abstract: A device and method to determine incoming communications is provided. A device in communication an array of antenna devices determines respective quality metric weights for respective signal data representing respective signals received by the antenna devices. The device applies the respective quality metric weights to the respective signal data to determine total received signal data. The device determines, based on the total received signal data, that the array of the antenna devices has received an incoming communication.

Abstract: A method and system for direct mode operation (DMO) of a talkgroup enables device to device (D2D) DMO operation leveraged from a Land Mobile Radio (LMR) system. The method includes scanning at a radio receiver a defined radio frequency spectrum; receiving at the radio receiver in the defined radio frequency spectrum a wake-up signal; identifying a talkgroup identifier in the wake-up signal, wherein the talkgroup identifier corresponds to a talkgroup being monitored by the radio receiver; in response to identifying the talkgroup identifier, decoding code sequences included in the wake-up signal; identifying in at least one of the code sequences both a center frequency and a transmission bandwidth of the DMO transmission; and tuning the radio receiver to receive the DMO transmission at the center frequency and transmission bandwidth.

Abstract: A method and system for direct mode operation (DMO) of a talkgroup enables device to device (D2D) DMO operation leveraged from a Land Mobile Radio (LMR) system. The method includes scanning at a radio receiver a defined radio frequency spectrum; receiving at the radio receiver in the defined radio frequency spectrum a wake-up signal; identifying a talkgroup identifier in the wake-up signal, wherein the talkgroup identifier corresponds to a talkgroup being monitored by the radio receiver; in response to identifying the talkgroup identifier, decoding code sequences included in the wake-up signal; identifying in at least one of the code sequences both a center frequency and a transmission bandwidth of the DMO transmission; and tuning the radio receiver to receive the DMO transmission at the center frequency and transmission bandwidth.

Abstract: A method (300, 400) and a non-incumbent system (102) that selects a pilot signal candidate within the RF spectrum, determines a first ratio between a measured total power within the RF spectrum and a measured power level of the pilot signal candidate, measures a first difference between the first ratio and an expected ratio, processes the first difference to select a threshold difference value, and outputs the threshold difference value.

Abstract: Efficient frequency spectrum sharing between at least one incumbent communication system(s) (102, 104) and at least one cognitive radio (CR) system (106, 108) is provided. The CR unit includes OFDM detection (216) for detecting the presence of OFDM signals which indicate the presence of an incumbent communication system within the shared spectrum. The CR system (106) updates channel occupancy information in response to the detected OFDM signals so as not to interfere with the incumbent communication systems (102, 104).

Abstract: A method for use in a digital communications receiver for controlling an input signal level (200) into an analog-to-digital converter (ADC) initially receives a sample sequence (201) where a threshold crossing rate is measured as a percentage samples of an input signal that exceed the threshold (203). The error between the measured threshold crossing rate and a desired reference threshold crossing rate is calculated (205) and an error signal is then utilized in a feedback loop to control the receiver gain such that the error is reduced (207).

Abstract: A method, system and apparatus for managing communication in a Public Safety Communication Network (PSCN). The PSCN includes a plurality of Mobile Stations (MSs) (110, 115, 120) and a master controller (105). The method includes initiating a communication between one or more MSs and the master controller using a primary channel (405). The primary channel corresponds to a primary frequency spectrum in the PSCN. The method further includes identifying one or more available channels in one or more of the primary frequency spectrum and a secondary frequency spectrum (410). Each of the primary frequency spectrum and the secondary frequency spectrum include one or more channels. Thereafter, a channel hopping pattern is generated for one or more MSs based on one or more available channels (415). The channel hopping pattern corresponds to a sequence of frequency hops for a MS.

Abstract: A method (20,200) and apparatus (10) for detecting and identifying spectrum opportunities, including the steps of communicating a location of at least one node (12) to at least one base station (14) (24), transmitting a list of at least one channel from the at least one base station (14) to the at least one node (12) (26), and sensing the at least one channel from the list by the at least one node (12) (34). The method (20,200) also includes the steps of determining if the at least one channel is in use, and if the at least one channel is in use, determining the user of the at least one channel that is in use (38).

Abstract: A method and apparatus for operation of a node within a mobile ad hoc cognitive radio network is provided. The method includes sensing at least one assigned communications channel. Sensing at least one assigned communications channel includes measuring a value of at least one parameter corresponding to the communications channel. The method further includes comparing the measured value of the at least one parameter with a set of stored values of the at least one parameter to determine a change in the measured values. Finally a sleep mode of the node is activated for a time period, wherein the time period is determined using the change in the measured values.

Abstract: A wireless communication network is provided in which a plurality of radio devices achieve frequency diversity. By utilizing cognitive capability within the radio devices to iteratively select frequency sets, a lowest cardinality frequency set is generated and used to communicate amongst the plurality of radio devices. Each radio device can have different hardware, as the iterative selection of frequency set can take into account the different hardware capabilities of the radio devices.

Abstract: An interference contribution associated with a selected subcarrier of a plurality of subcarriers associated with a previously transmitted OFDM symbol or a current OFDM symbol is determined. A fast Fourier transform (FFT) output for the current OFDM symbol is also determined. The interference contribution is subtracted from the FFT output of the current OFDM symbol to form a modified FFT output.

Abstract: Efficient frequency spectrum sharing between at least one incumbent communication system(s) (102, 104) and at least one cognitive radio (CR) system (106, 108) is provided. The CR unit includes OFDM detection (216) for detecting the presence of OFDM signals which indicate the presence of an incumbent communication system within the shared spectrum. The CR system (106) updates channel occupancy information in response to the detected OFDM signals so as not to interfere with the incumbent communication systems (102, 104).

Abstract: A method (300, 400) and a non-incumbent system (102) that selects a pilot signal candidate within the RF spectrum, determines a first ratio between a measured total power within the RF spectrum and a measured power level of the pilot signal candidate, measures a first difference between the first ratio and an expected ratio, processes the first difference to select a threshold difference value, and outputs the threshold difference value.

Abstract: A method and apparatus for operation of a node within a mobile ad hoc cognitive radio network is provided. The method includes sensing at least one assigned communications channel. Sensing at least one assigned communications channel includes measuring a value of at least one parameter corresponding to the communications channel. The method further includes comparing the measured value of the at least one parameter with a set of stored values of the at least one parameter to determine a change in the measured values. Finally a sleep mode of the node is activated for a time period, wherein the time period is determined using the change in the measured values.

Abstract: A method for use in a digital communications receiver for controlling an input signal level (200) into an analog-to-digital converter (ADC) initially receives a sample sequence (201) where a threshold crossing rate is measured as a percentage samples of an input signal that exceed the threshold (203). The error between the measured threshold crossing rate and a desired reference threshold crossing rate is calculated (205) and an error signal is then utilized in a feedback loop to control the receiver gain such that the error is reduced (207).

Abstract: A wireless communication network is provided in which a plurality of radio devices achieve frequency diversity. By utilizing cognitive capability within the radio devices to iteratively select frequency sets, a lowest cardinality frequency set is generated and used to communicate amongst the plurality of radio devices. Each radio device can have different hardware, as the iterative selection of frequency set can take into account the different hardware capabilities of the radio devices.

Abstract: A method, system and apparatus for managing communication in a Public Safety Communication Network (PSCN). The PSCN includes a plurality of Mobile Stations (MSs) (110, 115, 120) and a master controller (105). The method includes initiating a communication between one or more MSs and the master controller using a primary channel (405). The primary channel corresponds to a primary frequency spectrum in the PSCN. The method further includes identifying one or more available channels in one or more of the primary frequency spectrum and a secondary frequency spectrum (410). Each of the primary frequency spectrum and the secondary frequency spectrum include one or more channels. Thereafter, a channel hopping pattern is generated for one or more MSs based on one or more available channels (415). The channel hopping pattern corresponds to a sequence of frequency hops for a MS.

Abstract: A receiver configured for: a) receiving (410) a first OFDM symbol and generating a plurality of demodulated symbols for the first OFDM symbol; b) generating (420) decoder output code symbols corresponding to a subset of the plurality of demodulated symbols; c) determining (430) that a set of the decoder output code symbols make up a set of reference symbols corresponding to at least a portion of the subset of the plurality of demodulated symbols; d) generating (440) the set of reference symbols; e) generating (450) a set of channel estimates based on the set of reference symbols and the at least a portion of the subset of the plurality of demodulated symbols, for use in decoding a current OFDM symbol; and f) repeating steps b-e until a channel estimate for each demodulated symbol corresponding to the first OFDM symbol has been generated.

Abstract: A method (20,200) and apparatus (10) for detecting and identifying spectrum opportunities, including the steps of communicating a location of at least one node (12) to at least one base station (14) (24), transmitting a list of at least one channel from the at least one base station (14) to the at least one node (12) (26), and sensing the at least one channel from the list by the at least one node (12) (34). The method (20,200) also includes the steps of determining if the at least one channel is in use, and if the at least one channel is in use, determining the user of the at least one channel that is in use (38).

Abstract: A system and method for performing channel estimation. The system includes a receiver for decoding OFDM. Upon receiving an OFDM symbol, a plurality of demodulated subcarrier modulation symbols for the OFDM symbol are generated. The demodulated subcarrier modulation symbols are then decoded to generate decoder output code symbols. At least a portion of the decoder output code symbols are reencoded, interleaved, and mapped to a set of reference symbols, where the set of reference symbols correspond to at least a portion of the plurality of subcarriers. A first set of channel estimates is generated, based on at least a portion of the set of reference symbols and a corresponding portion of the plurality of demodulated symbols. Remaining channel estimates are then interpolated from the first set of estimates by filtering the first set of estimates. The channel estimates are then used in decoding a current OFDM symbol being received by the receiver.