| 5375140 |
Wireless direct sequence spread spectrum digital cellular telephone system |
| Dec-20-1994 |
The present invention is directed to novel implementation techniques which makes orthogonal CDMA practical in an a short range mobile telephone environment where significant multipath fading exists. Specifically,... |
| 5373531 |
Signal acquisition and reception method for a global positioning system signal |
| Dec-13-1994 |
A signal acquisition method for a GPS receiver which eliminates the necessity of a clock circuit for keeping the current time and also a backup battery for memory is disclosed. According to the signal... |
| 5371760 |
Method and apparatus for measuring the impulse response of a radio channel |
| Dec-6-1994 |
A system for measuring a multipath radio channel impulse response by cross-correlating digital samples of a received pseudo-random signal with a digital copy of the transmitted signal. A transmitter within... |
| 5369663 |
Spatial combiner for a digital VLF/LF receiver |
| Nov-29-1994 |
A spatial combiner for connection to a receiver used in conjunction with a lurality of direction-sensitive antennas for receiving a spread-spectrum communication signal in the presence of interference... |
| 5365551 |
Data communication transceiver using identification protocol |
| Nov-15-1994 |
One or more interrogating commander stations and an unknown plurality of responding responder stations coordinate use of a common communication medium. Each commander station and each responder station... |
| 5365550 |
Initial synchronization and tracking circuits for spread spectrum receivers |
| Nov-15-1994 |
A direct sequence digital spread spectrum receiver acquires and maintains synchronization in a reliable, yet simple manner, even under severe multipath and interference conditions. A sliding correlator... |
| 5365543 |
Transmitting circuit and receiving circuit |
| Nov-15-1994 |
In a first direct-sequence spread spectrum communication system having a transmission circuit where a data signal to be transmitted is coded by a first chip code signal and a receiving circuit for decoding... |
| 5363403 |
Spread spectrum CDMA subtractive interference canceler and method |
| Nov-8-1994 |
A spread-spectrum code division multiple access interference canceler for reducing interference in a direct sequence CDMA receiver having N chip-code channels. The interference canceler includes a plurality... |
| 5363404 |
Apparatus and method for conveying information in a communication network |
| Nov-8-1994 |
A direct sequence code-division multiple access (DS CDMA) communication system schedules conveyance of blocks (400) of information such that the blocks arrive at a base-site (130) just-in-time for transmission... |
| 5363402 |
HF radio apparatus operable in multiple communication modes |
| Nov-8-1994 |
An HF radio transceiving apparatus that maintains communication integrity by employing a plurality of receivers, each capable of operating in separate and independent communication modes. One embodiment... |
| 5363401 |
Mechanism for extracting hybrid (fh/ds) spread spectrum signals within multi-signal type environment |
| Nov-8-1994 |
Identification and extraction of hybrid, frequency-hopped direct sequence pseudo noise (FH/DS), signals from a multiband signal environment is effected by a sequential signal processing technique which... |
| 5363108 |
Time domain radio transmission system |
| Nov-8-1994 |
A time domain communications system wherein a broadband of time-spaced signals, essentially monocycle-like signals, are derived from applying stepped-in-amplitude signals to a broadband antenna, in this... |
| 5361276 |
All digital maximum likelihood based spread spectrum receiver |
| Nov-1-1994 |
A spread spectrum receiver for use in spread spectrum communication systems is disclosed. The spread spectrum receiver of the present invention includes an analog-to-digital converter for receiving an... |
| 5359625 |
Spread spectrum communication system particularly-suited for RF network communication |
| Oct-25-1994 |
Spread spectrum communication using direct sequences that approximate a swept frequency waveform in which successive square waves are formed by the chips making up the sequence, and in which the durations... |
| 5357541 |
Transceiver providing selectable frequencies and spreading sequences |
| Oct-18-1994 |
A transceiver for transmitting and receiving digital data is disclosed. The transceiver employs direct sequence spread spectrum communications techniques for reducing interference among multiple users... |
| 5353352 |
Multiple access coding for radio communications |
| Oct-4-1994 |
Individual information signals encoded with a common block error-correction code are assigned a unique scrambling mask, or signature sequence, taken from a set of scrambling masks having selected correlation... |
| 5353303 |
Technique for increasing the data rate in a spread spectrum data link |
| Oct-4-1994 |
A method for increasing the bit rate of a data link is to select two additional 31-bit chip code patterns that are orthogonal to the present two chip codes, and to each other. This method will not require... |
| 5353302 |
Signal despreader for CDMA systems |
| Oct-4-1994 |
A signal despreader for use in a CDMA system processes samples of the received signal with filtered replicas of the code coefficient sequences associated with the system users. The symbols transmitted... |
| 5353300 |
Communication method for an adaptive direct sequence CDMA communication system |
| Oct-4-1994 |
A communication method in an adaptive CDMA communication system (100) capable of communicating a direct sequence spread spectrum communication signals which comprise bit sequences coded with spreading... |
| 5353301 |
Method and apparatus for combining multipath spread-spectrum signals |
| Oct-4-1994 |
A method and apparatus for combining multipath spread-spectrum signals are provided. The multipath combining is accomplished by detecting an envelope of an input differential phase shift keyed signal communicated... |
| 5351269 |
Overlaying spread spectrum CDMA personal communications system |
| Sep-27-1994 |
A spread spectrum CDMA communications system for communicating data and/or digitized voice between a plurality of users to a plurality of PCN units. The spread spectrum communications system is located... |
| 5351270 |
Portable cellular telephone using spread spectrum communication with mobile transceiver |
| Sep-27-1994 |
A portable cellular telephone system including a stationary transceiver for radio communication with a plurality of mobile transceivers within a geographic cell, a mobile transceiver within said geographic... |
| 5349606 |
Apparatus for multipath DSSS communications |
| Sep-20-1994 |
Circuit for recovery of a plurality of multipath direct sequence spread spectrum signal components received over a time span, wherein the multipath signal components are components of a signal generated... |
| 5347536 |
Multipath noise reduction for spread spectrum signals |
| Sep-13-1994 |
The invention includes the concepts of early-prompt delay tracking, multipath correction of early-prompt delay tracking from correlation shape and carrier phase multipath correction. In early-prompt delay... |
| 5345471 |
Ultra-wideband receiver |
| Sep-6-1994 |
An ultra-wideband (UWB) receiver utilizes a strobed input line with a sampler connected to an amplifier. In a differential configuration, .+-.UWB inputs are connected to separate antennas or to two halves... |
| 5343494 |
Code division multiple access (CDMA) inbound messaging system utilizing over-the-air programming |
| Aug-30-1994 |
A method for receiving and processing data in a portable transceiver (20) comprises the steps of receiving (320) at least one information signal and decoding (325) the at least one information signal to... |
| 5343493 |
Personal assistance system and method for use with a cellular communication system |
| Aug-30-1994 |
A personal assistance system and method for use with a cellular communication system operating over a cellular communication band and having a plurality of cell-sites. A transceiver transmits to the cell-sites... |
| 5343495 |
Method of multipath dsss communications |
| Aug-30-1994 |
Method of demodulating a signal including a plurality of time-dispersed signal components such as resulting from receiving in a multipath environment. A plurality of correlators are provided. The period... |
| 5341423 |
Masked data transmission system |
| Aug-23-1994 |
A method and apparatus for masking the presence and content of data transmissions includes a mobile transmitter which encodes the data by means of a pseudorandom spreading (PRS) code having a chip rate,... |
| 5341396 |
Multi-rate spread system |
| Aug-23-1994 |
Apparatus and a method for transmitting a direct sequence, spread spectrum communication system signal. A transmitter (10) that receives a variable data rate information bearing input signal from a digital... |
| 5335278 |
Fraud prevention system and process for cellular mobile telephone networks |
| Aug-2-1994 |
An improved mobile telephone system, including a process and apparatus for detecting fraudulent requests for roamer cellular telephone services before the requested service is granted. The improvement... |
| 5317593 |
Communication device with code sequence and frequency selection system |
| May-31-1994 |
A code division multiple access (CDMA) communication system (10) for reuse of available spreading codes includes a first communication device (100) and a second communication device (106). The first and... |
| 5315616 |
Correlator for DSSS communications |
| May-24-1994 |
A correlator for processing a direct sequence spread spectrum communication system signal, wherein digital data comprised of data bits at a data bit rate is modulated by a first pseudo-noise code comprised... |
| 5315615 |
DSSS communications correlation |
| May-24-1994 |
Method of processing a direct sequence spread spectrum communication system signal wherein digital data comprised of data bits is modulated by a first pseudo-noise code comprised of a sequence of chips,... |
| 5313491 |
Acquisition method for DSSS communications |
| May-17-1994 |
Method for indicating the end of an acquisition procedure between a transmitter and receiver in a direct sequence spread spectrum communications system. At a transmitter, a first acquisition code having... |
| 5313490 |
Acquisition apparatus for DSSS communications |
| May-17-1994 |
Apparatus for indicating the end of an acquisition procedure between a transmitter and receiver in a direct sequence spread spectrum communications system. A transmitter generates a first acquisition code... |
| 5311542 |
Spread spectrum communication system |
| May-10-1994 |
A spread spectrum communication system having a plurality of transmitters at remote locations capable of transmitting information to one or more receivers during a plurality of information time durations.... |
| 5311544 |
Receiver of a direct sequence spread spectrum system |
| May-10-1994 |
A receiver of a direct sequence spread spectrum system includes a period counter for counting a period of a system clock, and outputting a data demodulation signal approximately every half-PN period, a... |
| 5311541 |
Frequency agile radio |
| May-10-1994 |
A frequency agile spread spectrum radio system which is capable of efficient frequency re-use and frequency sharing. The receiver adaptively learns which frequencies to avoid. The transmitter sends redundant... |
| 5309474 |
System and method for generating signal waveforms in a CDMA cellular telephone system |
| May-3-1994 |
A system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference... |
| 5307372 |
Radio transceiver for transmitting and receiving data packets |
| Apr-26-1994 |
An apparatus for transmitting and receiving packets of data among a multitude of base and remote units utilizing a frequency hopping technique. The apparatus uses a single clock source for synchronizing... |
| 5307370 |
Secure cordless radio-telephone |
| Apr-26-1994 |
A frequency-hopping cordless telephone system is described which adds digitized audio to a pseudorandom frequency hopping pattern for voice encryption. The randomly selected start point of a very long... |
| 5307371 |
Radio transceiver system |
| Apr-26-1994 |
A radio transceiver system is provided with transceivers for transmitting an outbound signal at least at one transmitting frequency and for receiving an inbound signal at least at one receiving frequency.... |
| 5305348 |
Spread-spectrum communication apparatus |
| Apr-19-1994 |
A spread-spectrum communication apparatus has code generators for generating spread-spectrum and reverse spread-spectrum codes. Rather than using a code generator which differs for every apparatus, the... |
| 5305347 |
Method of detecting the frequency deviation in digital communication transmissions |
| Apr-19-1994 |
The invention discloses a method of measuring the rough frequency deviation in digital communication transmissions with echo propagation, particularly in the short-wave domain. A repeatedly transmitted... |
| 5303259 |
Frequency-hopped electronic signal transmitter |
| Apr-12-1994 |
A multi-frequency electronic signal transmitter includes apparatus for transmitting an electronic signal on each of a plurality of transmission frequencies in succession such that the signal is detectable... |
| 5303258 |
Spread spectrum communications system |
| Apr-12-1994 |
A spread spectrum communications system includes: a transmitter having an input information a modulator for generating a spread spectrum signal in accordance with an input information signal together with... |
| 5303257 |
Carrier frequency correction for a DSSS communication system |
| Apr-12-1994 |
Method for carrier frequency correction in a direct sequence code division multiple access communication system having a carrier frequency, consisting of an expected carrier frequency and a carrier frequency... |
| 5299229 |
High rate-low rate PN code tracking system |
| Mar-29-1994 |
A high PN code rate receiving system is provided for receiving, recovering and tracking a high rate PN composite code comprising a low rate PN code combined with a high rate PN code and wherein the receiving... |
| 5299226 |
Adaptive power control for a spread spectrum communications system and method |
| Mar-29-1994 |
An apparatus for adaptive-power control of a spread-spectrum transmitter of a mobile station operating in a cellular-communications network using spread-spectrum modulation. A base station transmits a... |
