Abstract: There is disclosed a TDD frame transmission synchronization apparatus for use in a fixed wireless access network comprising a plurality of base stations capable of bidirectional time division duplex (TDD) communication with wireless access devices disposed at a plurality of subscriber premises. The TDD frame transmission synchronization apparatus comprises a frame allocation controller for receiving from a first radio frequency (RF) modem shelf associated with a first base station access requests generated by a first group of wireless access devices communicating with the first base station and determining from traffic requirements associated with the access requests a time duration of a longest downlink portion of TDD frames used by a first one of a plurality of RF modems in the RF modem shelf to communicate with a first wireless access device.

Abstract: There is disclosed a radio frequency (RF) modem shelf for use in a fixed wireless access network comprising a plurality of base stations capable of bidirectional time division duplex (TDD) communication with wireless access devices disposed at a plurality of subscriber premises. The radio frequency (RF) modem shelf comprises: a) a first RF modem for communicating with a plurality of the wireless access devices using TDD frames, each TDD frame having an uplink for receiving data and a downlink for transmitting data; and b) a modulation controller associated with the RF modem shelf for determining an optimum modulation configuration for each of the plurality of wireless access devices communicating with the first RF modem.

Abstract: Apparatus, and an associated method, for creating a profile associated with burst data signals communicated to a base station of a fixed wireless access communication system. The profile is created to facilitate receive operations performed upon subsequent bursts of the burst data signal. The profile is stored at a storage device and retrieved when subsequent bursts of the bursts data signal are received at the base station.

Abstract: Apparatus, and an associated method, for acting upon data signals received at a base station of a fixed wireless access communication system. A plurality of modems are positioned at the base station, and a controller controls to which modem that a data signal, transmitted by a particular subscriber station, is applied to a particular modem. Profiles relating to channel and signal characteristics are also maintained and used by the modem during demodulation operations.

Abstract: An apparatus, and an associated method, operates upon bursts of data signals received at a base station in a fixed wireless access communication system. A controller is provided in a base transceiver station that is capable of causing cyclo-stationary adaptive filtering to be performed upon successive bursts of data signals received at the base station. The cyclo-stationary filtering is performed to facilitate improved speed and accuracy by which the bursts are acted upon by the demodulator portion of a modem positioned at the base station.

Abstract: There is disclosed a transceiver for use in a base station (BS) of a fixed wireless network that communicates with a plurality of subscriber transceivers via time division duplex (TDD) channels.

Abstract: A system for keeping the surface temperature of an electric resistance-type heater element in a thermodilution catheter within safe physiological limits includes, in the preferred embodiment, a heater element core temperature monitor, a monitor for monitoring the power that is supplied to the heater element, and a surface temperature calculator for calculating the surface temperature of the heater element based on the core temperature, supplied power, and information representing the characteristics of the particular catheter under anticipated clinical conditions. A second aspect of the invention involves a system for determining the supply of power to the heater element based on the core temperature of the heater element. A third aspect of the invention involves a system readiness test for determining, in vivo, that the thermodilution catheter system is properly calibrated before the system is operational. Methods of operation for each of the above-referenced aspects of the invention are also disclosed.

Abstract: A system for keeping the surface temperature of an electric resistance-type heater element in a thermodilution catheter within safe physiological limits includes, in the preferred embodiment, a heater element core temperature monitor, a monitor for monitoring the power that is supplied to the heater element, and a surface temperature calculator for calculating the surface temperature of the heater element based on the core temperature, supplied power, and information representing the characteristics of the particular catheter under anticipated clinical conditions. A second aspect of the invention involves a system for determining the supply of power to the heater element based on the core temperature of the heater element. A third aspect of the invention involves a system readiness test for determining, in vivo, that the thermodilution catheter system is properly calibrated before the system is operational. Methods of operation for each of the above-referenced aspects of the invention are also disclosed.

Abstract: A system for keeping the surface temperature of an electric resistance-type heater element in a thermodilution catheter within safe physiological limits includes, in the preferred embodiment, a heater element core temperature monitor, a monitor for monitoring the power that is supplied to the heater element, and a surface temperature calculator for calculating the surface temperature of the heater element based on the core temperature, supplied power, and information representing the characteristics of the particular catheter under anticipated clinical conditions. A second aspect of the invention involves a system for determining the supply of power to the heater element based on the core temperature of the heater element. A third aspect of the invention involves is a system readiness test for determining, in vivo, that the thermodilution catheter system is properly calibrated before the system is operational. Methods of operation for each of the above-referenced aspects of the invention are also disclosed.

Abstract: Methods and apparatus for eliminating the effects of electrosurgical interference on continuous, heat-based cardiac output measurements employing several procedures, including the steps of (1) supplying power via an isolation transformer and carrier frequency to a catheter-mounted heating element; (2) measuring the voltage and current on the primary side of the isolation transformer; (3) determining the voltage and current on the secondary side of the transformer on the basis of the measured primary side voltage and current; and (4) calculating the power delivered to and resistance of the catheter-mounted heater on the basis of the secondary voltage and current. A heater power waveform generated with this process will be substantially free of electrical interference due to electrosurgical devices. Then, a system transfer function may be produced via signal processing techniques which involve cross-correlating the heater power waveform with the blood temperature waveform.

Abstract: An adaptive matched filter is described as a replacement for a signal replica filter of a maximum likelihood (ML) demodulator, the filter normally receiving an input data vector having signal and noise components. A symbol-justified input data vector is produced from the input data vector. This vector is then used to generate a weight vector. In a time-domain embodiment, the symbol-justified data vector is multiplied by the weight vector on a symbol-by-symbol basis to estimate the signal components of the output of a filter. In a frequency-domain implementation, multiplication is carried out on a symbol block-by-symbol block basis.