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 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 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 (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.

Abstract: Described is a method and an apparatus for performing the method to cancel interference caused by a windowing function applied to a signal prior to the signal being transmitted in a wireless communication system such as an OFDM system. The apparatus includes receiver apparatus that receives the signal to which the windowing function was applied. The apparatus further includes a processing device coupled to the receiver apparatus, and the processing device obtains (either by generating in substantially real time or retrieving from a storage device coupled to the processing device) a plurality of coefficients that are derived from the windowing function, and applies the coefficients to the received signal to cancel at least a portion of the interference from the received signal.

Abstract: A long code scrambler has been provided to scramble the data bits prior to QAM mapping. Different data rates are accommodated by using different long code m-tuples sampled at the modulation symbol rate, where m equals 2, 4 or 6 for 4, 16 or 64 QAM, respectively. In order to support 1XEV-DV users employing multiple Walsh code channels, a long code 6-tuple sample is permutated, to further randomize the QAM symbols. As appropriate for the modulation order, 2, 4 or 6 bits of the permutated 6-tuple are applied to the data sequence. That is, in addition to randomizing the modulation symbols for a given code channel, each code channel will likely have unique QAM symbols at any given symbol time.

Abstract: A method and apparatus for signal combining within a communication system is provided herein. The output of RAKE fingers is combined via a chip combiner. The combined chip stream can be despread with the appropriate Walsh code (defining a particular channel). The resulting symbol stream can then be deinterleaved and decoded.

Abstract: A receiving communication device synchronizes to a timing reference of a transmitting communication device based on a determined timing error. The receiving communication device determines the timing error by processing a synchronization signal via a first stage filtering and interpolation process that includes predetermined coefficients and a second stage interpolation process that includes a minimal number of dynamically determined coefficients. By dividing the process into a predetermined coefficient stage and a dynamically determined coefficient stage, the receiving communication device is able to make timing adjustments in a more efficient manner, that is, at a lesser processor loading, than a communication device in which all filtering and interpolation coefficients are dynamically determined.

Abstract: A long code scrambler has been provided to scramble the data bits prior to QAM mapping. Different data rates are accommodated by using different long code m-tuples sampled at the modulation symbol rate, where m equals 2, 4 or 6 for 4, 16 or 64 QAM, respectively. In order to support 1XEV-DV users employing multiple Walsh code channels, a long code 6-tuple sample is permutated, to further randomize the QAM symbols. As appropriate for the modulation order, 2, 4 or 6 bits of the permutated 6-tuple are applied to the data sequence. That is, in addition to randomizing the modulation symbols for a given code channel, each code channel will likely have unique QAM symbols at any given symbol time.

Abstract: A receiving communication device synchronizes to a timing reference of a transmitting communication device based on a determined timing error. The receiving communication device determines the timing error by processing a synchronization signal via a first stage filtering and interpolation process that includes predetermined coefficients and a second stage interpolation process that includes a minimal number of dynamically determined coefficients. By dividing the process into a predetermined coefficient stage and a dynamically determined coefficient stage, the receiving communication device is able to make timing adjustments in a more efficient manner, that is, at a lesser processor loading, than a communication device in which all filtering and interpolation coefficients are dynamically determined.

Abstract: A method and apparatus for signal combining within a communication system is provided herein. The output of RAKE fingers is combined via a chip combiner. The combined chip stream can be despread with the appropriate Walsh code (defining a particular channel). The resulting symbol stream can then be deinterleaved and decoded.

Abstract: A method of reducing power consumption in a communication device includes a step of acquiring a signal on a common pilot channel of a radio communication system. A next step includes detecting predetermined bits in the signal on the common pilot channel indicating activity on paging channels of the radio communication system. When no paging channel activity is indicated in the second step, a last step includes powering down portions of the electrical circuitry of the communication device so as to reduce power consumption, and when paging channel activity is indicated in the second step, a next step includes powering up portions of the electrical circuitry of the communication device such that those paging channels indicating activity are monitored by the communication device.

Abstract: A method and apparatus for compensating for input threshold variations in input buffers is provided. The method and apparatus compensate for input threshold variations by applying a bias voltage on a known capacitance of an RC calibration circuit using, for example, a pulse width modulator. The bias voltage helps ensure that the time to charge the known capacitance from the bias voltage to the input threshold voltage of the input buffer is independent of the threshold voltage. The bias voltage is chosen using an iterative process in which the time to charge from the bias voltage to the threshold voltage is compared with a reference time. The bias voltage is adjusted based on the comparison.

Abstract: A programmable divide-by-N or divide-by-N+1/2 circuit is responsive to an input clock signal and to a plurality of binary-coded data signals corresponding to the divisor for providing an output clock signal having a frequency which is the frequency of the input clock signal divided by the value encoded on the data signals. The circuit includes two separate down counters 10, 12--one decrementing on the positive-going edge of the input clock signal and the other decrementing on the negative-going edge of the input clock signal.If the divisor is an integer N, the negative-clocked circuitry 12 is disabled and the positive-clocked circuit 10 counts down from N to 1 continuously. If the divisor is N+1/2, both counter circuits are used. In this case, both counters are preset with the value N, the positive-edge-triggered counter 10 decrements from N to zero while the negative-edge-triggered counter 12 decrements from N to one.

Abstract: An adapter module for converting a Class B alarm system to Class A operation. The module includes a first pair of terminals connected to corresponding terminals of a Class B control panel, and second and third pairs of terminals to which Class A alarm loops are connected, one terminal of each of the second and third pairs of terminals being directly electrically connected to a separate terminal of the first pair of terminals.

Abstract: A fail-safe alarm system includes a device which allows current to flow in only one direction to insure that the supervisory current in an alarm circuit is flowing in the intended direction rather than in a wrong direction caused by a miswiring.