Abstract: A method and system for performing sequence time domain reflectometry to determine the location of line anomalies in a communication channel is disclosed. In one embodiment, the system generates a sequence signal and transmits the sequence signal over a channel that is the subject of the sequence time domain reflectometry analysis. The system monitors for and receives one or more reflections, collectively a reflection signal, and presents the reflection signal to a reflection processing module. The module also has access to the original sequence signal that was transmitted over the channel. Various methods of processing the reflection signal are available to determine the location of the line anomalies. In one embodiment, the reflection signal is correlated with the original sequence signal to generate a correlated signal. The system performs signal analysis on the correlated signal to determine a time value between the start of the reflection signal and the subsequent points of correlation.

Abstract: A method and system for performing sequence time domain reflectometry over a communication channel to determine the location of line anomalies in the communication channel is disclosed. In one embodiment, the system generates a sequence signal and transmits the sequence signal over an optical channel. The system receives one or more reflection signals over the optical channel and performs reflection signal processing on the reflection signal. In one embodiment, the optical reflection is transformed to an electrical signal and correlated with the original sequence signal to generate a correlated signal. The time between the start of the reflection signal and a subsequent point of correlation and the rate of propagation reveals a line anomaly location. A circulator, beam splitter, or any other similar device may direct the reflection signal to the apparatus configured to perform reflection signal processing.

Abstract: A system, method, and signal are disclosed for line probing. The invention provides an improved signal for line probing having desirable characteristics. In various embodiments the signal comprises a periodic sequence having good autocorrelation characteristics. The periodic sequence of the invention provides a faster and more accurate evaluation of the channel. Another embodiment of the invention comprises processing of the received sequence to determine a desired or maximum data rate for the line or channel. The invention also provides an evaluation and calculation of the noise on the line or channel.

Abstract: A method and an apparatus for decoding trellis coded direct sequence spread spectrum communication signals are provided. A transmitted QPSK signal is received. Binary phase-shift keyed (BPSK) despreading is performed on the QPSK signal. The BPSK despreading comprises correlating the in-phase and the quadrature components of the received QPSK signal with independent PN sequences for the each of the in-phase and the quadrature components. The despread signal is then demultiplexed, and the pilot signal and the BPSK data signal are recovered. The recovered pilot signal is used to provide a channel phase estimate and a channel magnitude estimate. The recovered BPSK data signal is demodulated, despread, and decoded. The despreading and decoding comprises determining a number of cross-correlation terms of the received signal using a number of transmitted biorthogonal Walsh sequences. The cross-correlation terms are used as the branch metrics in a maximum likelihood decoding algorithm.

Abstract: In a CDMA cellular system, a method for estimating the amplitude of a traffic channel based on a pilot signal received from two or more basestations. Each channel in a RAKE receiver is provided with a data signal received on a traffic channel and a pilot signal received on a pilot channel. A comparison is made between the product of the pilot signal and the data signal versus the product of the pilot signal and an estimate of the traffic channel amplitude. The estimate of the traffic channel amplitude drives a feedback loop to refine the comparison and the data signal is weighted by the traffic channel amplitude estimate and combined with weighted data signals in the other channels of the RAKE receiver.

Abstract: A method and an apparatus for encoding of trellis coded direct sequence spread spectrum communication signals are provided. An input data bit sequence is received into a transmitter where it is encoded and modulated using trellis code modulation. The encoding comprises encoding the signal using a convolutional coder having a rate equal to 1/log2 (M), where M is a number of biorthogonal Walsh sequences. The encoded and modulated signal is spread by mapping a number of branches of the trellis code to a number of biorthogonal Walsh sequences. The mapping comprises labeling the branches of the trellis code using the biorthogonal Walsh sequences. This mapping uses the output of a convolutional coder as a memory address where the memory address contains one of a number of biorthogonal Walsh sequences. The spread signal may be a binary phase-shift keyed (BPSK) data signal, but is not so limited.

Abstract: A method and an apparatus for demodulating trellis coded direct sequence spread spectrum communication signals are provided. A transmitted QPSK signal is received. Binary phase-shift keyed (BPSK) despreading is performed on the QPSK signal. The BPSK despreading includes correlating the in-phase and the quadrature components of the received QPSK signal with independent PN sequences for the each of the in-phase and the quadrature components. The despread signal is then demultiplexed, and the pilot signal and the BPSK data signal are recovered. The recovered pilot signal is used to provide a channel phase estimate and a channel magnitude estimate. The recovered BPSK data signal is demodulated, despread, and decoded. The despreading and decoding includes determining a number of cross-correlation terms of the received signal using a number of transmitted biorthogonal Walsh sequences. The cross-correlation terms are used as the branch metrics in a maximum likelihood decoding algorithm.

Abstract: A satellite communication system comprising of a central hub/gateway station and remote very small aperture terminal (VSAT) stations. VSAT inbound transmissions are spread in bandwidth using an assigned PN code sequence. This sequence is derived as a cyclic function of a base sequence for use by the group of VSATs. The gateway transmits a continuous outbound signal that functions as the network frequency and timing reference. In addition, the gateway periodically forms timing and frequency error estimates on each VSAT transmission and broadcasts these results over the outbound channel to the VSATs. Use of the outbound reference coupled with these time and frequency measurements enable all VSAT inbound transmissions within a group to be bit synchronized. Bit level synchronization enable the system to gain the full advantage of the correlation properties of the cyclic codes to improve multiple access performance as compared to asynchronous or chip synchronous code division multiple access (CDMA) techniques.

Abstract: Patients in hospitals are provided with identification bracelets which display a patient identity number in a machine-readable form, such as a bar code. Blood or other samples are taken at bedside from patients by a technician, nurse, or the like who carries a microprocessor-operated device which optically scans the coded patient identification bracelet. When the patient ID bracelet is read, the device lists the different blood tubes that are to be filled on a display screen. The device has a fixedly mounted onboard scanner which scans a preprinted bar code on the specimen tube which bar code identifies the type of tube being used. Just before, or after, the specimen is drawn, the tube is read by the onboard scanner, and a label is printed and placed on the tube, which label includes the patient's name; the patient's I.D. number; the tests to be performed on the specimen sample; the time and date the specimen was drawn; and the size and type of tube.

Abstract: A pressure-vacuum chamber is mounted in a sheet metal housing having acoustical padding on inner surfaces of walls. The chamber has two vacuum-formed truncated cone members and a longitudinally extending axial partition plate sealingly mounted in inward facing grooves in the members. A flow-through blower is sealingly mounted in an aperture in the plate.

Abstract: A single line, pressure-pressure, pneumatic tube system having a pair of terminals each being capable of dispatching or receiving carriers. Each terminal provided with a blower to provide air flow, tubing connecting the two terminals, a pair of inline valves in the tubing, one facing in one direction and the other in the opposite direction. The valves being so designed that the one near the dispatching terminal automatically closes to permit build up of pressure and the one near the receiving terminal opens to exhaust pressure and slow the travel of the carrier as it approaches the receiving terminal, the terminal having a bleed-off orifice to assure carrier arrival.

Abstract: A pressure-vacuum chamber is mounted in a sheet metal housing having acoustical padding on inner surfaces of walls. The chamber has two vacuum-formed truncated cone members and a longitudinally extending axial partition plate sealingly mounted in inward facing grooves in the members. A flow-through blower is sealingly mounted in aperture in the plate.

Abstract: A single line, pressure-pressure, pneumatic tube system having a pair of terminals each being capable of dispatching or receiving carriers. Each terminal provided with a blower to provide air flow, tubing connecting the two terminals, a pair of inline valves in the tubing, one facing in one direction and the other in the opposite direction. The valves being so designed that the one near the dispatching terminal automatically closes to permit build up of pressure and the one near the receiving terminal opens to exhaust pressure and slow the travel of the carrier as it approaches the receiving terminal, the terminal having a bleed-off orifice to assure carrier arrival.

Abstract: A single line (pressure-vacuum) pneumatic tube system capable of incorporating one or more novel intermediate stations. A unique pressure-vacuum chamber and a novel air shifter valve in the central station provides either pressure or vacuum for the system without turbulence or significant pressure drop. An air relief valve in the tubing significantly reduces noise at the end station. The end station is provided with a valve for return air. The system is unitized eliminating custom design of simple systems.

Abstract: A single line (pressure-vaccum) pneumatic tube system capable of incorporating one or more novel intermediate stations. A unique pressure-vacuum chamber and a novel air shifter valve in the central station provides either pressure or vacuum for the system without turbulence or significant pressure drop. An air relief valve in the tubing significantly reduces noise at the end station. The end station is provided with a valve for return air. The system is unitized eliminating custom design of simple systems.

Abstract: A single line (pressure-vacuum) pneumatic tube system capable of incorporating one or more novel intermediate stations. A unique pressure-vacuum chamber and a novel air shifter valve in the central station provides either pressure or vacuum for the system without turbulence or significant pressure drop. An air relief valve in the tubing significantly reduces noise at the end station. The end station is provided with a valve for return air. The system is unitized eliminating custom design of simple systems.