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6477157 |
Dedicated control channel handoff in CDMA communication system
A handoff method in a CDMA communication system using Walsh codes and quasi-orthogonal codes. To implement a handoff, a new base station to which a call is switched notifies a serving base station...
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6473467 |
Method and apparatus for measuring reporting channel state information in a high efficiency, high performance communications system
Channel state information (CSI) can be used by a communications system to precondition transmissions between transmitter units and receiver units. In one aspect of the invention, disjoint...
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6473394 |
Apparatus and method for bandwidth management in a multi-point OFDM/DMT digital communications system
A multi-point communications system having an allocated total bandwidth is set forth. The system comprises a head end unit disposed at a primary site. The head end unit includes a receiver for...
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6459684 |
Multiplexed codec for an ADSL system
An ADSL central office transmission system for transmitting downstream DMT signals to a plurality of remote ADSL transceiver is disclosed. The system includes a DMT digital signal transceiver that...
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6459693 |
Device and method for cancelling code interference in a CDMA communication system
A device and method for cancelling code interference in a receiver of a CDMA (Code Division Multiple Access) communication system simultaneously using orthogonal codes and quasi-orthogonal codes...
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6459679 |
Method and apparatus for synchronizing orthogonal frequency division multiplexing (OFDM) receiver
A method and apparatus for synchronizing an OFDM receiver is provided. The method includes the steps of: (a) receiving an OFDM reference symbol before user data OFDM symbols, the OFDM reference...
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6456612 |
Device and method for generating short PN code in a mobile communication system
A short PN code generating device in a mobile communication network having a N× CDMA communication system performing spreading at an N× chip rate using a short PN code of chip length N×2 k and...
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6449244 |
Implementation of orthogonal narrowband channels in a digital demodulator
An innovative channelizer design methodology is provided to adjust the narrowband channel frequency spacing and processing algorithm in order to develop a configurable multi-rate channelizer ( 20 )...
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6449245 |
Signal receiving apparatus and method and providing medium
An intermediate frequency signal of an OFDM signal received by a tuner ( 2 ) is multiplied by a carrier wave by a multiplier ( 3 ) and a multiplier ( 4 ) to thereby generate an OFDM signal in a...
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6442130 |
System for interference cancellation
A spatial processor that exploits signals that arrive via multiple outputs of a communication channel to provide soft decision values useful to a trellis or Viterbi decoder. A spatial processor may...
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6434131 |
CDMA method with increased capacity
Using CDMA encoding and spectrum spreading with a factor N, more than N messages are transmitted although N is a theoretical limit for this type of encoding. Encoding uses orthogonal sequences for...
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6430148 |
Multidirectional communication systems
In a multi-directional orthogonal frequency division modulation (OFDM) communication system, for example, on a digital subscriber line, an uplink channel is provided by a first group of the OFDM...
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6430149 |
Processing circuits for complex operation
A processing circuit for a complex operation, includes buffer memories in which a pair of quadrature demodulation output signals based on a modulated carrier wave signal obtained in accordance with...
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6426939 |
Method for preventing a collision of an extended orthogonal code
A method for preventing a collision of an extended orthogonal code uses an extended orthogonal code applying a hadamard code, and prevents an extended orthogonal code's collision occurred by a...
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6424618 |
Code generating method and code selecting method
The present invention relates to a code generating method for combining an orthogonal code for CDMA having a specific spreading factor and its polarity inverted spreading code to generate another...
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6414936 |
Method of estimating carrier frequency offset in an orthogonal frequency division multiplexing system
Disclosed is a method of estimating carrier frequency offset in an OFDM system. The method includes the steps of forming one OFDM symbol which has M repeated identical signal block, being a base...
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6400679 |
Communication resource allocation method and apparatus
A communication resource allocation method and apparatus services, in even the code division multiple access method (CDMA) considered to be suitable for radio transmission using mobile stations...
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6396802 |
Data transmission method with a plurality of frequency bands
The invention relates to a data transmission method in which the data to be transmitted are divided into a plurality of subchannels each with a normal component and a quadrature component that is...
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6396803 |
Modulation methods and structures for wireless communication systems and transceivers
Wireless communication methods and structures are provided that enhance communication robustness while reducing cost. They communicate downstream data with orthogonal frequency division...
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6392988 |
Transmitter architecture employing space time spreading and orthogonal transmit diversity techniques
Disclosed is a common transmitter architecture having incorporated both open loop transmit diversity schemes using a plurality of binary switches. Employment of binary switches allows for the...
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6385187 |
Device and method for generating spread spectrum signal using pseudo-orthogonal code in CDMA mobile communications system
A device and method for generating a pseudo-orthogonal code for use in orthogonally spreading channel data in a CDMA mobile communications system. M orthogonal codes are selected from N orthogonal...
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6317412 |
Increased capacity in an OCDMA system for frequency isolation
A spread spectrum OCDMA communication system in which multiple base stations or beams from a satellite are deployed in a "cellular" coverage structure, system capacity is increased by dividing the...
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6317422 |
Methods and apparatus of N-chip resistant spreading in CDMA systems
Methods and apparatus for generating spreading codes in a CDMA system are disclosed in accordance with the teachings of the present invention wherein the system includes a pseudonoise (PN) code...
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6314082 |
Broadcast network selection techniques for radiocommunication systems
Hybrid cellular/broadcast systems are described wherein broadcast (simulcast) techniques are used to provide high data rate, downlink radiocommunication service. Various techniques for selecting an...
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6314113 |
Method of determining a symbol transmission format in a transmission system and system
A method and apparatus for determining the transmission format of complex symbols in a received signal which is formatted in complex symbol blocks. Each block has a first occurrence (GI k ) of a...
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6314125 |
Method and apparatus for the construction and transmission of binary quasi orthogonal vectors
A transmission method in a communications system has an orthogonal code vector for transmitting message signals. A first vector matrix is formed using a first series of cyclic shifts of a sequence...
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6310856 |
CDMA communications system having a searcher receiver and method therefor
A wideband CDMA handset (20) has a receiver (50) which simplifies initial sequence acquisition. The receiver (50) includes an efficient searcher receiver (54) which searches for long code mask...
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6301221 |
Methods and apparatus for encoding data
In a coded orthogonal frequency division multiplex (COFDM) system n-bit data words are encoded as m -symbol code words (binary, quaternary, octary, etc.). The code words are selected for desired...
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6298035 |
Estimation of two propagation channels in OFDM
A method and apparatus for estimating separate channel frequency responses for two channels in an orthogonal frequency division multiplexing system with two transmitters is disclosed. The channel...
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6278685 |
Robust transmission mode
An interleaving/de-interleaving scheme for providing redundancy with both time and frequency diversity to data in OFDM symbols in a data transmission system. On the transmit side, encoded data to...
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6278686 |
Construction of a multicarrier signal
The invention concerns a multicarrier signal designed to be transmitted to digital receivers, especially in a non-stationary transmission channel, corresponding to the frequency multiplexing of...
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6262971 |
Multichannel spread-spectrum packet
Encoding and transmitting packet-switched, spread-spectrum data. Data are encoded for privacy and to restrict intelligent receipt of the data to the intended recipient. The encoded data are...
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6256508 |
Simultaneous broadcasting system, transmitter and receiver therefor
A simultaneous broadcasting system, a transmitter, and a receiver therefor use a first frequency bandwidth for a wide area broadcasting and a second frequency bandwidth for a local area...
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6201785 |
Process for transmitting a digitized signal according to OFDM type multicarrier modulation, transmitter and receiver for the implementation of the said process
The present invention relates to a process for transmitting a digitized signal according to OFDM (Orthogonal Frequency Division Multiplexing) type multicarrier modulation using N orthogonal...
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6198782 |
Estimation of frequency offsets in OFDM communication systems
Apparatus for estimating carrier and clock frequency offsets in OFDM systems employs a maximun likelihood estimator operation on the demodulated signals. The invention has the benefit of low...
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6192056 |
Demodulating apparatus and demodulating method
A demodulating apparatus and a demodulating method includes a correlation detector for detecting a correlation between a guard section of the symbol of a digital orthogonal frequency division...
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6178158 |
Method and apparatus for transmission and reception
In a method for transmission and reception over N transmission channels, the transmitting side performs orthonormal transform processing of N-channel modulated signals so that the resulting...
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6175559 |
Method for generating preamble sequences in a code division multiple access system
The present invention provides a method for generating preamble sequences in a code division multiple access system. The method includes forming an outer code in a mobile station. The mobile...
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6167024 |
Multiple channel control using orthogonally modulated coded drive signals
An orthogonal pilot tone servo controller provides a servo control loop for each tap in a delay line processor where each servo acquires its independence from the other tap's servos utilizing an...
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6167418 |
Byte-switching arithmetic unit
The present invention provides a byte-switching arithmetic unit comprising at least three stages, each of which has a plurality of two-input selectors operable in a predetermined minimum bit width...
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6163524 |
Code allocation in CDMA
In spread spectrum communications, a method for allocating and re-allocating channelization codes to new and existing channels in a way that makes the maximum number of codes available at a given...
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6160791 |
Transmission system for the transmission of power control information in an OFDM system
A transmission method for transmitting signals on the basis of an orthogonal frequency division multiplex (OFDM) system is disclosed. Information to be transmitted in the signals is modulated onto...
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6157611 |
Method and apparatus for transmission and construction of quasi orthogonal vectors
A transmission method in a communications system having orthogonal code vectors for transmitting message signals is taught. The method includes forming a first vector matrix using a first series of...
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6148007 |
Method for data transmission in a digital audio broadcasting system
A method of broadcasting digitally encoded information includes the transmission of a plurality of orthogonal frequency division multiplexed sub-carriers. The sub-carriers are modulated by a...
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6141332 |
Orthogonal code synchronization system and method for spread spectrum CDMA communications
A cellular radio system in which a base station receiver can receive, on the reverse link, data from a mobile terminal in one of four control modes. In the first mode, the mobile terminal sends an...
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6125124 |
Synchronization and sampling frequency in an apparatus receiving OFDM modulated transmissions
An OFDM receiver determines (12; 27) the pulse response of a radio channel and locates (13; 14) its starting point, end point and the maximum and its value. The difference between the end point and...
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6122246 |
Apparatus and method for clock synchronization in a multi-point OFDM/DMT digital communications system
A multi-point communications system is set forth herein. The communications system comprises a transmitter for transmitting OFDM/DMT symbols over a predetermined number of bins across a...
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6118805 |
Method and apparatus for performing frequency hopping adaptation
The invention relates to a communication system (300) having a receiver (304) that is capable of performing targeted interference suppression. An interference classifier (314) within the receiver...
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6115354 |
Multiple carrier transmission in common-wave networks
In order to prevent wanted signal capacity from being reduced during OFDM modulation of digital coded data, control symbol protecting intervals in the frame head of each OFDM transmission frame are...
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6111919 |
Synchronization of OFDM signals
A method is described for temporally aligning a received symbol that is transmitted via orthogonal channels, e.g., OFDM channels, with a reference symbol and/or an earlier received symbol. The...
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