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| Number | Title | Issue Date |
| 5175557 | Two channel global positioning system receiver A method and apparatus for operating a two channel digital global positioning system receiver for receiving coded satellite signals from each of a plurality of satellites, where the signals exhibit Doppler shifts. The method comprises the steps of continu... | 12/29/1992 |
| 5166952 | Method and apparatus for the reception and demodulation of spread spectrum radio signals 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 fo... | 11/24/1992 |
| 5105436 | Spread spectrum receiver A spread spectrum receiver using a correlator includes a pattern matching circuit for deciding presence or absence of a pulse output which is obtained upon coincidence between the pattern of a correlator output and a predetermined pattern, so as to switch... | 04/14/1992 |
| 5105437 | Programmable digital acquisition and tracking controller A novel programmable digital acquisition and tracking controller is coupled to the input signal level from the demodulator of a communications receiver and provides programmable signal level threshold detectors and detection intervals adapted to produce a... | 04/14/1992 |
| 5099493 | Multiple signal receiver for direct sequence, code division multiple access, spread spectrum signals Disclosed is a multiple-signal receiver system for direct sequence, code division multiple access (CDMA), spread spectrum (SS) signals. The receiver is structured to overcome inter-signal interference during signal acquisition and data reception even when... | 03/24/1992 |
| 5093841 | Clock acquisition in a spread spectrum system A circuit and method is disclosed for recovering the transmitter clock at a receiver in a direct sequence spread spectrum communication system where a transmitter and receiver run independent clocks of nominally the same frequency. At the receiver, to sel... | 03/03/1992 |
| 5090023 | Spread spectrum communication system The correlation between a PN code pattern of the synchronization preamble data of an incoming spread spectrum signal and a reference PN code pattern generated on the reception side is detected by using an SAW convolver. The gate length of the SAW convolve... | 02/18/1992 |
| 5081462 | Method of deriving phase of pseudo-random code signal in global positioning system receiver A method, for use in a receiver for the NAVSTAR global positioning system (GPS), of deriving successive values of phase of a received pseudo-random code signal following a momentary interruption of satellite signal reception, with the effects of signal no... | 01/14/1992 |
| 5067136 | Wireless alarm system A wireless alarm system using spread spectrum transmitters, fast frequency shift keying, spread spectrum receivers and computer with a display. The spread spectrum transmitter includes an oscillator coupled to a microprocessor with chip code generation me... | 11/19/1991 |
| 5048053 | Detecting and tracking circuit for component PN codes In a demodulator circuit for receiving a direct sequence spread spectrum signal having composite PN codes, there is provided a novel detecting and tracking circuit for faster acquisition of the component PN codes. The first component code of the received ... | 09/10/1991 |
| 4953179 | Energy-dispersal signal rejection circuit and method An energy-dispersal signal rejection circuit adapted for use in a direct-broadcast-from-satellite system rejects an energy-dispersal signal from an input signal which includes a video signal composed with the energy-dispersal signal by generating a cancel... | 08/28/1990 |
| 4943974 | Detection of burst signal transmissions A method is disclosed for detecting the presence of and synchronizing to burst transmissions which contain repeated acquisition codes. The received signal is applied as an input to a surface acoustic wave (SAW) filter which is matched to detect one repeti... | 07/24/1990 |
| 4942590 | Optimum clock generator in data communication A clock generator in a data receiver for generating an optimum PN code clock used by a spectrum spread (55) communication receiver. The generator comprises a clock generator for generating a plurality of clocks having different phases; a synchronization s... | 07/17/1990 |
| 4933953 | Initial synchronization in spread spectrum receiver An initial synchronization system for spread spectrum communication including a despreader-demodulator circuit for despreading and demodulating an input signal according to a despread control signal, a decoder circuit for decoding a data signal demodulate... | 06/12/1990 |
| 4932036 | Spread spectrum squaring loop with invalid phase measurement rejection A squaring loop for a GPS receiver locks to a carrier that is bi-phase modulated with a PRN acquisition code and a data message. The receive signal is down converted and hard limited and phase measurements are made between the rising edges of a local cloc... | 06/05/1990 |
| 4918706 | Spread spectrum long loop receiver A Long Loop GPS receiver converts the pseudo random noise code bi-phase modulated input signal to a first IF frequency. The first IF is correlated against a duplicate of the pseudo random noise code that modulates the input signal. The correlator output i... | 04/17/1990 |
| 4918707 | Spread spectrum demodulating device for spread spectrum communication system A spread spectrum demodulating device applicable to a spread spectrum communications system for demodulating a spread spectrum signal by inverse spread. A spread clock is directly recovered from a received spread spectrum signal to thereby generate a pred... | 04/17/1990 |
| 4912721 | Cable television spread spectrum data transmission apparatus Apparatus for transmitting data spread across at least a portion of the bandwidth of a cable television channel comprises a carrier signal oscillator, a frequency divider, a pseudorandom sequence generator and two exclusive OR gates. A first exclusive OR ... | 03/27/1990 |
| 4903279 | Receiver for spread spectrum communication and receiving method for the same The present invention discloses a receiver and a receiving method for spread spectrum communication for use in the digital communication system. The receiver basically comprises a receiving circuit, a spread signal distributing circuit, a pseudo noise sig... | 02/20/1990 |
| 4884284 | Spread spectrum receiver A receiver in a spread spectrum communication system includes: a noise detector for detecting noises of a spread spectrum input signal; an initial synchronization circuit including a correlator for detecting a correlation of the spread spectrum input sign... | 11/28/1989 |
| 4875221 | Spread spectrum receiver A spread spectrum receiver including a convolver for establishing initial synchronization of received and reference pseudo noise codes and a delay lock circuit or other circuit for subsequently tracking the phase difference between both pseudo noise codes... | 10/17/1989 |
| 4852121 | Coherent pseudonoise code tracking loop A coherent pseudonoise code (PN) tracking loop is provided with apparatus for sensing the absence of PN transition in the incoming data stream to the tracking loop and for switching OFF the data stream to prevent phase error distortion and inherent noise ... | 07/25/1989 |
| 4841545 | Synchronous tracking device for direct spread spectrum receiver A synchronous tracking device for a receiver in a direct-spread spectrum communication system in which a carrier frequency and a pseudo noise code for spreading it are coherent. A first circuit tracks the pseudo noise code in the received signal for a pre... | 06/20/1989 |
| 4774715 | Device for demodulating a spread spectrum signal Circuitry for receiving and demodulating a spread spectrum signal integrates signal acquisition and tracking functions and also accommodates signal drift. Two data decoding signals are generated which correspond to the pseudo noise code used to modulate t... | 09/27/1988 |
| 4761795 | Receiver for bandspread signals An improved receiver for modulated bandspread carrier signals is disclosed. The invention includes an antenna for intercepting a plurality of modulated carrier signals bandspread at a first clock rate; a radio frequency section in communication with the a... | 08/02/1988 |
| 4759034 | Multi-step spread spectrum communication apparatus In a pseudo-random communication system, a transmitter-generated encoded signal is to be correlated with a receiver-generated similarly encoded signal for recognizing synchronization of the transmitted and received signals in the presence of undesired rec... | 07/19/1988 |
| 4672629 | Receiver for bandspread signals A receiver for bandspread signals having a pseudo-random code stored in the receiver for synchronization with a pseudo-random code (PRC) of a received and modulated signal for recovering the modulation utilizing control loops. The modulated carrier signal... | 06/09/1987 |
| 4649549 | Apparatus for synchronizing linear PN sequences A system and method are disclosed for synchronizning the linear PN sequences contained in a received spread spectrum signal, characterized by the provision of a resident PN generator that is responsive to the chip rate clock for producing a replica of the... | 03/10/1987 |
| 4641322 | System for carrying out spread spectrum communication through an electric power line A communication system for carrying out communication between a plurality of stations through an electric power line operating in a commercial power frequency band. Spread spectrum modulation of an information signal, employing a pseudorandom code sequenc... | 02/03/1987 |
| 4630283 | Fast acquisition burst mode spread spectrum communications system with pilot carrier A high frequency code division multiple access spread spectrum (CDMA SS) communications system includes multiple transmitters and their associated receivers, and a pilot carrier source. In order to reduce errors in the receiver IF frequency due to unavoid... | 12/16/1986 |
| 4621365 | Synchronization preamble correlation detector and frequency estimator A device is disclosed which simultaneously performs sync preamble correlation detection and frequency offset estimation functions for a spread spectrum receiver. The device performs a parallel frequency search, executed by a plurality of frequency sensiti... | 11/04/1986 |
| 4559633 | Spread spectrum system A spread-spectrum communication system includes a transmitter for transmitting a spectrum-spread signal and a receiver for receiving the data signal. To establish synchronism between the signals transmitted and received, the receiver includes a first loop... | 12/17/1985 |
| 4538280 | Coherent spread spectrum pseudonoise tracking loop A detector (20) is provided for use in a communication receiver where a received spread spectrum data signal is detected using a locally generated reference signal to decode the data signal. The detector (20) includes first (22) and second channels (24) a... | 08/27/1985 |
| 4530103 | Method and apparatus for baseband tracking of a PN code sequence in a spread spectrum receiver A method and apparatus for baseband synchronizing of a local PN code sequence with a received PN code sequence incorporated in a received spread spectrum signal is provided. The received spread spectrum signal is translated to baseband to produce an I (in... | 07/16/1985 |
| 4527275 | Correlation data communications system A digital data communications system employing correlation detection is disclosed as comprising an encoding system which encodes successive k-bit data words from a data source into predetermined start-stop phases of either a 2k -bit repeating p... | 07/02/1985 |
| 4435822 | Coherent spread spectrum receiving apparatus In a digital data acquisition system, there is provided a coherent direct sequence spread spectrum receiving system. The coherent receiving system comprises an independent carrier tracking loop and three independent branches for detecting and locking on t... | 03/06/1984 |
| 4423517 | Code sequence synchronization system for spread spectrum communication receiver A synchronization system for a spread spectrum communication receiver generates a receiving code sequence which is identical to an input code sequence and then varies the timing of the receiving code sequence using a correlator until the two code sequence... | 12/27/1983 |
| 4385401 | Three-state digital mixer-driver circuit A mixer-driver circuit in a code correlator of a spread-spectrum communications system simultaneously multiplies an input RF signal with two phase-offset digitally encoded bit streams. A double-balanced mixer is driven with the difference of the digital s... | 05/24/1983 |
| 4351064 | Communication There is disclosed frequency modulation (FM) or phase modulation (PM) communication with a receiver having a limiter, in spread-spectrum operation for security purposes. The spectrum is spread on transmission by superimposing a psuedo-noise code modulatio... | 09/21/1982 |
| 4346475 | Data transmission system operating on the spread spectrum principle According to the invention, it is proposed to use the code words D as the spreading word for the spectrum. The auto-correlation function of these words have zero values for all even temporary shifts other than the zero shift, the auto-correlation function... | 08/24/1982 |
