Abstract: A high capacity wireless ultra-wideband (UWB) data communication system includes a transmitter having a signal generator for supplying UWB signals and a receiver for receiving the UWB signals. In one embodiment, the system also includes at least two antennas at the transmitter and/or at the receiver. The transmit antennas are configured so that the cross-correlation between their emissions is sufficiently low that reception of the signals is substantially improved. The receive antennas likewise exhibit low cross-correlation.

Abstract: A communication protocol for ultra-wideband communications is provided. The present invention provides compatibility and interoperability between ultra-wideband communications devices within various types of networks. In one embodiment, combined, or interleaved data frames having both high and low data transfer rate capability are provided. The low data transfer rate may be used for initial discovery of the type of network that is being accessed, and the high data transfer rate may be used to quickly transfer data within networks that have a high data transfer rate capability. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

Abstract: Systems and methods are described for transmitting and receiving spread spectrum signals using continuous waveforms. A method of transmitting a spread spectrum signal includes: generating a plurality of substantially continuous waveforms; summing the plurality of substantially continuous waveforms; modulating the summed plurality of substantially continuous waveforms to generate the spread spectrum signal; and transmitting the spread spectrum signal. A method of receiving a spread spectrum signal includes: generating a plurality of substantially continuous waveforms; summing the plurality of substantially continuous waveforms; modulating the summed plurality of substantially continuous waveforms with a code; mixing the modulated summed plurality of substantially continuous waveforms with the spread spectrum signal to produce a baseband signal; integrating the baseband signal; and detecting data.

Abstract: An RF transmitter includes a reference signal generator, a signal generator, and a mixer. The reference signal generator provides a reference signal that has a prescribed or desired frequency. The signal generator provides an operating signal in response to a selection signal. The operating signal has a frequency that equals the frequency of the reference signal multiplied by a number. The mixer mixes the operating signal with another signal to generate a transmission signal. An RF receiver includes a first mixer, a second mixer, an integrator/sampler, and a signal generator. The first mixer receives as its inputs an input RF signal and a second input signal, and mixes its input signals to generate a mixed signal. The integrator/sampler receives the mixed signal and processes it to provide an output signal. The signal generator provides an operating signal in response to a selection signal. The operating signal has a frequency equal to the frequency of a reference signal, multiplied by a number.

Abstract: A communication transmitter apparatus includes a reference clock generator, a harmonic signal generator, and a modulator. The reference clock generator provides a reference clock signal that has a prescribed frequency. The harmonic signal generator provides one or more harmonic signals of the reference clock signal. The modulator modulates the one or more harmonic signals with an input signal to generate an output signal. A corresponding communication receiver apparatus receives the output signal of the communication transmitter apparatus.

Abstract: A method and apparatus for time-scale modification of speech using a modified version of the Waveform Similarity based Overlap-Add technique (WSOLA) comprises the steps of storing a portion of an input speech signal in a memory, analyzing the portion of the input speech signal to determined at least one filtered pitch value, calculating an estimated pitch value (12) from the at least one filtered pitch value, determining a segment size (14) in response to the estimated pitch value (12), the segment size (14) having a value greater than the estimated pitch value (12), and time-scale compressing (18) the input speech signal in response to the segment size determined.

Abstract: The present invention comprises a method for compressing a plurality of voice signals within a voice communication resource (see FIG. 6) having a given bandwidth within a voice communication system (100). The method comprises the steps of subchanneling the voice communication resource into a plurality of subchannels (441, 442, 443), placing a pair of the plurality of voice signals (401, 402) on a subchannel (441); modulating the pair of the plurality of voice signals (401, 402) about a pilot signal (581) within the subchannel (441) using single sideband modulation; and compressing the time of each of the voice signals (401, 402) within the plurality of subchannels (441, 442, 443), wherein these step provide a compressed voice signal.

Abstract: A modulation scheme (600) useful in a voice paging system in which both of two orthogonal modulation components (500 and 510) are used to carry two halves of a single voice message destined for a receiver, or two separate voice messages for a receiver. The single voice message is transmitted in half the time.

Abstract: A satellite communication system (100) includes a satellite (102) in a predefined orbit projecting a plurality of beams (1-48) designating a coverage area (115). The satellite (102) has a communication device (200), a frequency synthesizer (222) for setting a frequency of the communication device for communicating via a beam of the plurality of beams (1-48) and a controller (216) coupled to the frequency synthesizer (222) for compensating for a Doppler frequency shift associated with the beam.

Abstract: A radio paging system includes one or more transmitters (12) for sending radio signals to pagers (14) within a paging service area (10). Receivers (22) are located within the service area to receive low power transmissions from the pagers. These receivers are coupled to omnidirectional antennas (24, 26) that are disposed in pairs to form a two branch diversity antenna system. Each pair of antennas is located in a cell that forms part of a four cell cluster (66), and each pair of antennas is located on an axis (42) running through its cell. The axes are selected to provide a high and uniform level of diversity gain throughout the cluster.

Abstract: A messaging system (500) for transmitting a message to a subscriber unit (312). The messaging system (500) includes a plurality of geographically distributed messaging transmitters (302-310), each transmitter designed to transmit in a first modulation format, such as FM, during a first transmission portion (102) including address information; and in a second modulation format, such as OFDM, during a second transmission portion (104) including message data (110) transmitted in frames. The address information includes message characterization information (108) defining a predetermined frame rate. The second transmission portion (104) includes message data (110) transmitted in frames representing a time sequence of N data bits at the predetermined frame rate and provides a plurality of carrier frequencies related to a frequency domain representation of the time sequence of data bits. The predetermined frame rate numerically matches the predetermined symbol rate.

Abstract: An antenna (105) for receiving radio frequency (RF) signals includes a conductive element (300) having a first electrical length and a first operating impedance and a transmission line (315) having a second electrical length and a second operating impedance for resonating the conductive element (300) at a predetermined operating frequency. A coaxial element (305) having a third electrical length is coupled to the conductive element (300) and the transmission line element (315) for converting the first operating impedance to the second operating impedance. When the conductive element (300) is resonated, the first, second, and third electrical lengths are substantially equal to a quarter wavelength or an odd multiple thereof at the predetermined operating frequency.

Abstract: A method and apparatus in a data communication receiver (100) for diversity reception of a radio signal including a predictably repetitive, predetermined data bit pattern (304) comprises a processor (114) controlling (600) an antenna switch (106) to select between a first antenna feed (102) and a second antenna feed (104) as a momentary source of the radio signal during transmissions of the predetermined data bit pattern (304). The radio signal received from the momentary source is monitored by a data receiver (110) during the transmission of the predetermined bit pattern (304) to derive the data therefrom, and at least one bit error count is determined (604, 610) by the processor (114). After completion of the predetermined bit pattern (304), an antenna feed (102, 104) for the radio signal is selected (616, 620) in response to the at least one bit error count.

Abstract: A satellite receiver system provides acquisition and frequency tracking of a Doppler-shifted radio signal received from an orbiting satellite. The satellite receiver system includes a Costas phase-lock loop that receives the radio signal and provides an error signal at an error signal output for controlling a conversion frequency generated by a voltage controlled oscillator. The voltage controlled oscillator is coupled to the Costas phase-lock loop and generates the conversion frequency for down-converting the radio signal in the Costas phase-lock loop. The satellite receiver system further includes a Doppler frequency acquisition and tracking element coupled to the voltage controlled oscillator. The Doppler frequency acquisition and tracking element adjusts the conversion frequency to compensate for a Doppler frequency shift occurring in the radio signal due to orbital motion of the orbiting satellite.

Abstract: An antenna has a quarter wave resonant strip (10) and first and second parasitically excited strips (12 and 14) resonant at a lower and upper frequency, respectively, of the antenna bandwidth. The strips (10, 12 and 14) have trim tabs (20, 22 and 24) for adjusting the resonant frequency of each strip. The location of a feed (30) is set to provide a desired impedance match for use by a radio (60) such as a pager. A ground plane (40) provides a grounding for the strips (10, 12 and 14) and inhibits undesirable radio frequency interaction between the radio (60) and the strips (10, 12 and 14).

Abstract: A radio communication device (600) comprises a microstrip antenna (300) having a planar antenna element (302) and a ground plane (314) coupled to the planar antenna element (302). The microstrip antenna further comprises a dielectric material (304) positioned between the planar antenna element (302) and the ground plane (314), and a primary receiver element (325, 326, 328) mechanically coupled to the ground plane (314). The microstrip antenna (300) further comprises a feeder (308, 310) electrically coupled between the planar antenna element (302) and the primary receiver element (325, 326, 328) for feeding an intercepted radio signal therebetween for down conversion by the primary receiver element (325, 326, 328). The radio communication device (600) also comprises a secondary receiver element (828) coupled to the primary receiver element (325, 326, 328) for demodulating the intercepted radio signal after down conversion by the primary receiver element (325, 326, 328).

Abstract: A data communication receiver (100) includes a first antenna feed (106) coupled to a first receiver element (110) for demodulating (502) a radio signal containing data bits and for deriving a first phase-locked loop error signal. The data communication receiver (100) also includes a second antenna feed (108) coupled to a second receiver element (112) for demodulating (502) the radio signal and for deriving a second phase-locked loop error signal. A received signal strength indicator (134, 144) measures signal strength of the radio signal from the first antenna feed (106) during reception of a data bit, and concurrently measures signal strength from the second antenna feed (108). A processor (146) then defines (506, 508, 512) the data bit as received from the antenna feed (106, 108) having the greater signal strength to be the optimum data bit.

Abstract: A radio-frequency amplifier (50) has an impedance transformation network (66) with a control input (70) for controlling the transformation characteristic of the transformation network (66). The radio-frequency amplifier (50) amplifies an input signal to produce an amplified radio-frequency output signal to a load (68). The control circuit selects a power level for the output signal, in response to a control signal, by transforming the impedance of the load to a transformed impedance at the output of the radio-frequency amplifier, so that the efficiency of the radio-frequency amplifier is not substantially degraded as the power level for the output signal is changed.

Abstract: A dual mode communication receiver a receiver for receiving information transmitted in a first and second modulation format on a common channel, a first demodulator for detecting information transmitted in the first modulation format, and a second demodulator, responsive to the information detected in the first modulation format, for detecting information transmitted in the second modulation format. A power conservation circuit is also provided for selectively supplying power to the first and second demodulators for enabling the detecting of the information transmitted in the first modulation format and the second modulation format, respectively.

Abstract: A loop antenna includes a circuit board having a ground plane layer. A formed loop is located on one side of the circuit board and a transmission line is located on the opposite side of the circuit board. Capacitors interconnect the ends of the formed loop and the transmission line. The transmission line is a microstrip formed by the ground plane layer in a microstrip portion.The circuit board includes RF circuitry that is located on the side of the circuit board opposite to the transmission line so that the ground plane shields the circuitry from the transmission line.