Abstract: A method of diagnosis is disclosed. The method comprises: acquiring an absolute component and a phase component of an input signal indicative of an impedance of an organ of a subject; determining baseline blood flow of the subject based on the phase component; determining transient changes in blood flow based on at least the absolute component; and displaying the baseline blood flow and the transient changes in blood flow.

Abstract: A system for monitoring hemodynamics of a subject is disclosed. The system comprises: a signal generating system configured for providing at least an output electric signal and transmitting the output signal to an organ of the subject. The system also comprises a demodulation system configured for receiving an input electrical signal sensed from the organ responsively to the output electric signal, and for modulating the input signal using the output signal to provide an in-phase component and a quadrature component of the input signal. The system also comprises a processing system configured for monitoring the hemodynamics based on the in-phase and the quadrature components.

Abstract: The method includes sending a request for permission to transmit by each ready node in the wireless network. Each ready node is a node of the wireless network ready to transmit, each request identifies a node in the network that is the destination, and each request is sent over a control channel. An iterative process based on priorities determined for the ready nodes is then performed to determine which ready nodes to block from transmission and which ready nodes to clear for transmission. Transmissions are sent over a payload channel from ready nodes in the clear to transmit state.

Abstract: A method of diagnosis is disclosed. The method comprises: acquiring an absolute component and a phase component of an input signal indicative of an impedance of an organ of a subject; determining baseline blood flow of the subject based on the phase component; determining transient changes in blood flow based on at least the absolute component; and displaying the baseline blood flow and the transient changes in blood flow.

Abstract: In a method of improving system throughput while reducing packet delay for users of a wireless communication system, a user may be selected from a user population based on a parameter that is tracked for each user of the user population. A preferred beam for the user may be determined based on a highest running average data rate from each beam of a finite plurality of selectable beams so as to maximize the selected user's chances to be scheduled to receive the next packet. The preferred beam may be used for transmitting a pilot signal for scheduling a user in the user population to receive a next transmission on the preferred beam.

Abstract: The method includes sending a request for permission to transmit by each ready node in the wireless network. Each ready node is a node of the wireless network ready to transmit, each request identifies a node in the network that is the destination, and each request is sent over a control channel. An iterative process based on priorities determined for the ready nodes is then performed to determine which ready nodes to block from transmission and which ready nodes to clear for transmission. Transmissions are sent over a payload channel from ready nodes in the clear to transmit state.

Abstract: In a method of determining a beam to be generated for a user, a user may be selected from a user population based on a parameter that is tracked for each user in the user population, and a beam preferred by the selected user may be determined. The preferred beam may be generated and used by a base station to transmit a pilot signal to the user population. Each user of the user population responds to the pilot signal. The base station may run a scheduling algorithm and schedule a user based on feedback received from all the users in the user population, and information may be transmitted to the scheduled user using the preferred beam.

Abstract: In a method of improving system throughput while reducing packet delay for users of a wireless communication system, a user may be selected from a user population based on a parameter that is tracked for each user of the user population. A preferred beam for the user may be determined based on a highest running average data rate from each beam of a finite plurality of selectable beams so as to maximize the selected user's chances to be scheduled to receive the next packet. The preferred beam may be used for transmitting a pilot signal for scheduling a user in the user population to receive a next transmission on the preferred beam.

Abstract: A time-division-multiplexed fixed wireless loop system and methods therefor are disclosed. The system comprises a plurality of cells each having a base station and a plurality of terminals. The base station includes a steerable and adjustable multibeam antenna for communicating with each of the terminals, which have fixed antennas. A cell controller associated with each base station allocates communication time slots so as to minimize mutual interference between base station/terminal links sharing the same time slot. Slot assignment is based on regional, periodically updated interference measurements that are stored in data bases.

Abstract: In a method of determining a beam to be generated for a user, a user may be selected from a user population based on a parameter that is tracked for each user in the user population, and a beam preferred by the selected user may be determined. The preferred beam may be generated and used by a base station to transmit a pilot signal to the user population. Each user of the user population responds to the pilot signal. The base station may run a scheduling algorithm and schedule a user based on feedback received from all the users in the user population, and information may be transmitted to the scheduled user using the preferred beam.

Abstract: A frequency and phase estimator simultaneously estimates the frequency and phase of an MPSK modulated signal with a frequency uncertainty range on the order of the symbol rate. The estimator defines a plurality of contiguous bands within the frequency uncertainty range of the signal, estimates the frequency to one of the bands, and utilizes the frequency estimate to derive a phase estimate. In a preferred embodiment, a plurality of signal samples of the frequency shifted signal in each of said bands are accumulated to produce a vector for each band, and the frequency estimate is selected in one of said bands, based upon the magnitude of the corresponding vector. The phase is estimated from the argument of the corresponding vector. The present invention is particularly suited for burst modems or TDMA systems, where frequency and phase estimates must be derived reliably from a limited number of incoming symbols at the beginning of each burst.

Abstract: Without intercell coordination on a per communication request basis, channel assignment can be efficiently performed by developing for each cell, or a sector thereof when the cells are sectorized using directional antennas, a priority list of groups of channels, and selecting a channel to be assigned in response to a request for service from the highest priority group which has available channels at the time of the service request. The priority lists are developed based on various interference measurements that are made. The priority lists tend to remain the same for relatively long periods of time. However, periodically, the priority lists should be redetermined to insure that the best lists are being employed. For example the lists may need to be changed due to new construction or to seasonal vegetation changes which may affect the interference experienced in the system. Advantageously, system capacity under peak concentrated load conditions may increase.

Abstract: A frequency and phase estimator simultaneously estimates the frequency and phase of an MPSK modulated signal with a frequency uncertainty range on the order of the symbol rate. The estimator defines a plurality of contiguous bands within the frequency uncertainty range of the signal, estimates the frequency to one of the bands, and utilizes the frequency estimate to derive a phase estimate. In a preferred embodiment, a plurality of signal samples of the frequency shifted signal in each of said bands are accumulated to produce a vector for each band, and the frequency estimate is selected in one of said bands, based upon the magnitude of the corresponding vector. The phase is estimated from the argument of the corresponding vector. The present invention is particularly suited for burst modems or TDMA systems, where frequency and phase estimates must be derived reliably from a limited number of incoming symbols at the beginning of each burst.

Abstract: A frequency and phase estimator simultaneously estimates the frequency and phase of an MPSK modulated signal with a frequency uncertainty range on the order of the symbol rate. The estimator defines a plurality of contiguous bands within the frequency uncertainty range of the signal, estimates the frequency to one of the bands, and utilizes the frequency estimate to derive a phase estimate. In a preferred embodiment, a plurality of signal samples of the frequency shifted signal in each of said bands are accumulated to produce a vector for each band, and the frequency estimate is selected in one of said bands, based upon the magnitude of the corresponding vector. The phase is estimated from the argument of the corresponding vector. The present invention is particularly suited for burst modems or TDMA systems, where frequency and phase estimates must be derived reliably from a limited number of incoming symbols at the beginning of each burst.

Abstract: A time-division-multiplexed fixed wireless loop system and methods therefor are disclosed. The system comprises a plurality of cells each having a base station and a plurality of terminals. The base station includes a steerable and adjustable multibeam antenna for communicating with each of the terminals, which have fixed antennas. A cell controller associated with each base station allocates communication time slots so as to minimize mutual interference between base station/terminal links sharing the same time slot. Slot assignment is based on regional, periodically updated interference measurements that are stored in data bases.

Abstract: In a base station for providing wireless cellular service, an antenna arrangement is employed to transmit information to Mobile terminals, e.g., cellular radiotelephones, in a cell. The cell is divided into sectors. The antenna arrangement includes a number of antennas, each of which is used to serve one or more of the sectors. However, transmission of an antenna to a sector corresponding thereto is interfered by transmissions of other antennas to their corresponding sectors. To reduce such inter-sector interference in each sector, each antenna is designed to maximize beam efficiency of the sector, which is defined as a ratio of the power transmitted to the sector by the corresponding antenna to the total power radiated from the antenna.

Abstract: A time-division-multiplexed fixed wireless loop system and methods therefor are disclosed. The system comprises a plurality of cells each having a base station and a plurality of terminals. The base station includes a steerable and adjustable multibeam antenna for communicating with each of the terminals, which have fixed antennas. A cell controller associated with each base station allocates communication time slots so as to minimize mutual interference between base station/terminal links sharing the same time slot. Slot assignment is based on regional, periodically updated interference measurements that are stored in data bases.

Abstract: A spread spectrum receiver correlator for a with filters matched to transmitter chip codes are implemented in digital circuits along with a digital circuit for acquisition and tracking of the arrival times of the chip codes. The digital circuit implementations are used for the noncoherent demodulation of pulse position spread spectrum modulation signals where the pulse is a carrier modulator by a chip code and for the noncoherent demodulation of multiple chip code modulation signals where each information symbol is represented by one of several chip codes modulating a carrier.

Abstract: A spread spectrum receiver with filters matched to transmitter chip codes are implemented in digital circuits along with a digital circuit for acquisition and tracking of the arrival times of the chip codes. The digital circuit implementations are used for the noncoherent demodulation of pulse position spread spectrum modulation signals where the pulse is a carrier modulator by a chip code and for the noncoherent demodulation of multiple chip code modulation signals where each information symbol is represented by one of several chip codes modulating a carrier.

Abstract: A spread spectrum receiver with filters matched to transmitter chip codes are implemented in digital circuits along with a digital circuit for acquisition and tracking of the arrival times of the chip codes. The digital circuit implementations are used for the noncoherent demodulation of pulse position spread spectrum modulation signals where the pulse is a carrier modulator by a chip code and for the noncoherent demodulation of multiple chip code modulation signals where each information symbol is represented by one of several chip codes modulating a carrier.