Pilot Patents (Class 370/500)
  • Patent number: 7242722
    Abstract: In an OFDM system the same Walsh code is used at the same time for a plurality of transmitters. The multiple transmitters can be from the same, or different devices (e.g., different base stations on the downlink, different terminals on the uplink). Each subcarrier/antenna combination will share a similar pilot Walsh code, except for the fact that the scrambled spread pilot signals will be phase shifted on some subcarriers of some antennas, based on the subcarrier/antenna combination.
    Type: Grant
    Filed: September 21, 2004
    Date of Patent: July 10, 2007
    Assignee: Motorola, Inc.
    Inventors: Thomas P. Krauss, Kevin L. Baum, Vijay Nangia
  • Patent number: 7236502
    Abstract: This invention discloses a set of internal signaling (i.e., management primitives) to support a clock-synchronization protocol for wirelessly synchronizing clock registers of wired or wireless nodes via a wireless local area network (i.e., 802.11 network). The clock synchronization is performed between two higher-layer protocol entities residing within two different wireless stations (STAs).
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: June 26, 2007
    Assignee: Koninklijke Philips Electronics N. V.
    Inventors: Javier Del Prado Pavon, Sunghyun Choi
  • Patent number: 7149207
    Abstract: An effective data multiplexing method wherein an error correction ability is exerted at the maximum so that data transmission quality is improved and a data transmitting method in which an interleaving process applicable to data transmission using interpolation pilot signal is performed are provided. The data multiplexing method includes the steps of: coding input data for each input channel; multiplexing said data which is coded; performing an interleaving process on said data which is multiplexed; and outputting said data. In the data transmitting method, when an interleaving process is performed, an interleaver is used in which the number of columns of the interleaver is twice as many as the number of slots of a frame.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: December 12, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando
  • Patent number: 7142529
    Abstract: An effective data multiplexing method wherein an error correction ability is exerted at the maximum so that data transmission quality is improved and a data transmitting method in which an interleaving process applicable to data transmission using interpolation pilot signal is performed are provided. The data multiplexing method includes the steps of: coding input data for each input channel; multiplexing said data which is coded; performing an interleaving process on said data which is multiplexed; and outputting said data. In the data transmitting method, when an interleaving process is performed, an interleaver is used in which the number of columns of the interleaver is twice as many as the number of slots of a frame.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: November 28, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando
  • Patent number: 7139261
    Abstract: An effective data multiplexing method wherein an error correction ability is exerted at the maximum so that data transmission quality is improved and a data transmitting method in which an interleaving process applicable to data transmission using interpolation pilot signal is performed are provided. The data multiplexing method includes the steps of: coding input data for each input channel; multiplexing said data which is coded; performing an interleaving process on said data which is multiplexed; and outputting said data. In the data transmitting method, when an interleaving process is performed, an interleaver is used in which the number of columns of the interleaver is twice as many as the number of slots of a frame.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: November 21, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando
  • Patent number: 7106783
    Abstract: The present invention discloses a method for searching multipaths of a mobile communication system, which includes the steps of: performing a coherent detection on a reversed I and Q channel signals of a DPCCH transmitted form a mobile station, multiplying the detected signal by a pilot pattern to accumulate a pilot symbol section in a corresponding section, and performing a coherent accumulation on the other symbol section in a symbol basis; calculating energy value for each coherently accumulated I and Q channel signals; multiplying the calculated energy values by a weight that has been multiplied by the pilot symbol section and another weight that has been multiplied by the other symbol section, respectively; noncoherently accumulating the energy values multiplied by variable weights, and saving the energy values; comparing the saved energy values with a periodically designated threshold; and searching timing information as many as a number of fingers in order of highest energy value according to the compa
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: September 12, 2006
    Assignee: LG Electronics Inc.
    Inventors: Kyung Sam Seo, Dong Jo Park
  • Patent number: 7096017
    Abstract: A method and system for synchronizing scan opportunities in a mobile communications system. Time slots are sent between a mobile subscriber and an associated base station wherein the mobile subscriber corresponds to a scan group. The number of time slots sent between the mobile subscriber and the associated base station is counted. Based upon the count, the scan group of the mobile subscriber, a scan rate, and a scan opportunity divisor, a scan opportunity is determined. If it is a scan opportunity, a scan is performed of a neighboring base station.
    Type: Grant
    Filed: April 8, 2004
    Date of Patent: August 22, 2006
    Assignee: Motorola, Inc.
    Inventors: Stanko Jelavic, Apoorv Chaudhri, Alan P. Conrad
  • Patent number: 7065055
    Abstract: Method and apparatus for minimizing the processing delay incurred by an IC receiver over conventional receivers in a CDMA cellular system are disclosed. The method and apparatus involve operating the conventional receiver and the IC receiver in parallel to each other. Data from the conventional receiver are then used to supplement data from the IC receiver in order to minimize the delays incurred by the IC receiver.
    Type: Grant
    Filed: September 18, 2000
    Date of Patent: June 20, 2006
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Jonas Karlsson, Riaz Esmailzadeh
  • Patent number: 7050405
    Abstract: Novel data transmission method and apparatus in a communication system require novel method and apparatus for power control and rate of data determination, which are disclosed.
    Type: Grant
    Filed: December 6, 2002
    Date of Patent: May 23, 2006
    Assignee: Qualcomm Incorporated
    Inventors: Rashid Ahmed Attar, Naga Bhushan
  • Patent number: 7006468
    Abstract: A wireless communication system is provided that includes a plurality of origination stations and at least one terminal. The plurality of origination stations each communicate a signal comprising a regular page message over respective regular paging channels and a quick paging channel page message over respective quick paging channels. The terminal, when in an idle state during which an RF receiver is off, simultaneously monitors each of the quick paging channels for their respective quick paging channel page messages.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: February 28, 2006
    Assignee: QUALCOMM, Incorporated
    Inventors: Tao Chen, Jun Wang, Edward G. Tiedemann, Jr.
  • Patent number: 6996160
    Abstract: A channel estimation method which reduces the strain on resources of a Rake receiver using a complex weight gain (CWG) algorithm. In one embodiment, a non-adaptive algorithm is used to average blocks of pilot symbols from several slots. In another embodiment, an adaptive algorithm implements sliding window averaging or a recursive filter. Using a CWG algorithm reduces the memory and processor requirements of the Rake receiver.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: February 7, 2006
    Assignee: InterDigital Technology Corporation
    Inventors: Bin Li, Alexander Reznik
  • Patent number: 6985469
    Abstract: A method and circuit for adaptively estimating channel conditions of a pilot channel in a wireless communication system. The method includes estimating channel statistics of the pilot channel, and adaptively filtering the pilot channel in response to the estimated channel statistics. The estimation is performed by filtering a channel signal derived from the pilot channel to determine an estimated channel mean and an estimated channel covariance. In order to perform the adaptive filtering, the present invention partitions the pilot channel into one or more time slots and weights each time slot according to the channel statistics. Thus, an advantage of the present invention is that it automatically and continually updates the pilot filter parameters in order to optimize the pilot filter performance over a broad range of channel conditions.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: January 10, 2006
    Assignee: Qualcomm Inc
    Inventor: Gilbert Leung
  • Patent number: 6956842
    Abstract: An effective data multiplexing method wherein an error correction ability is exerted at the maximum so that data transmission quality is improved and a data transmitting method in which an interleaving process applicable to data transmission using interpolation pilot signal is performed are provided. The data multiplexing method includes the steps of: coding input data for each input channel; multiplexing said data which is coded; performing an interleaving process on said data which is multiplexed; and outputting said data. In the data transmitting method, when an interleaving process is performed, an interleaver is used in which the number of columns of the interleaver is twice as many as the number of slots of a frame.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: October 18, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando
  • Patent number: 6952417
    Abstract: A system and method selectively establishes data communications, such as XDSL services, between data devices and a network switch. Status of the data devices are monitored and active data devices are connected to a data branch for data communications. Data devices which are inactive may remain connected to the data branch, if available, or may be switched to a pilot branch. While disconnected from the pilot branch, the system may detect a signal from the data device indicating that the device is going active. If pilot signals are being used, the pilot signals between a data device and the network switch are monitored to determine when the data device is going active. Once detected, the data device is connected to the data branch. Alternately, if pilot signals are not being used, the system monitors the connection with the data device for any signals, such as a wake-up signal, which indicates that the data device is going active.
    Type: Grant
    Filed: March 13, 2000
    Date of Patent: October 4, 2005
    Assignee: Lucent Technologies Inc.
    Inventor: Carl Robert Posthuma
  • Patent number: 6937640
    Abstract: There is provided a method and apparatus for selecting an appropriate base station and an optimal data rate to provide a voice service and a data service based on a voice service load in a CDMA system. A base station transmits two pilot signals orthogonally spread with different orthogonal codes in association with its voice service load, and a mobile station estimates the voice service load based on a pilot power ratio.
    Type: Grant
    Filed: June 15, 2001
    Date of Patent: August 30, 2005
    Assignee: Samsung Electronics Co., LTD
    Inventors: Yu-Suk Yun, Soon-Young Yoon, Hee-Won Kang, Jae-Heung Yeom, Sang-Hyun Yang, Hoon Huh
  • Patent number: 6909761
    Abstract: A time division multiple access communication system is provided having multiple sub-channels according to known quadrature amplitude modulation techniques. Each sub-channel has a pre-determined time duration and is divided by a pre-determined number of symbol position time divisions. The symbol positions carry color codes and ACP codes in addition to sync, pilot and data symbols. Pilot symbols in the second half of the slot are replaced with dual purpose color code and ACP symbols. The dual purpose symbols are either modulated with a lower order modulation than data symbols or are repeated values of dedicated symbols located earlier in the same slot, or both. Slot throughput is attained with a minimal bit error rate penalty.
    Type: Grant
    Filed: December 19, 2002
    Date of Patent: June 21, 2005
    Assignee: Motorola, Inc.
    Inventors: Michael N. Kloos, Michael S. Palac, Yashpal Thind
  • Patent number: 6904079
    Abstract: A technique for efficient implementation of pilot signals on a reverse link in a wireless communication system. An access channel is defined for the reverse link such that within each frame, or epoch, a portion is dedicated to sending only pilot symbols. Another portion of the frame is reserved for sending mostly data symbols; however, within this second portion of the frame, additional pilot symbols are interleaved among the data symbols. The pilot symbol or preamble portion of the access channel frame allows for efficient acquisition of the access signal at the base station, while providing a timing reference for determining the effects of multipath fading. In particular, a pilot correlation filter provides a phase estimate from the pilot symbols in the preamble portion, which is then used to decode the data symbols in the payload portion. An access acquisition portion of the receiver uses the phase estimates provided by the pilot correlation filter to process the output of a data symbol correlation filter.
    Type: Grant
    Filed: January 19, 2001
    Date of Patent: June 7, 2005
    Assignee: IPR Licensing, Inc.
    Inventors: John E. Hoffmann, George Rodney Nelson, Jr., James A. Proctor, Jr., Antoine J. Rouphael
  • Patent number: 6873829
    Abstract: An apparatus for generating a plurality of beacon signals for use in a code division multiple access (CDMA) base station includes: a level controller for controlling a level of each of a plurality of transmit intermediate frequency (TxIF) signals based on a level control signal, thereby generating level-controlled TxIF signals; a frequency converter for converting a frequency of each of the level-controlled TxIF signals received from the level controller based on a frequency control signal, thereby generating a beacon transmit radio frequency (TxRF) signal time-divisionally; a time division controller for generating the level control signal and the frequency control signal based on a system synchronization signal and predetermined control information; and a control information storing unit for storing the predetermined control information.
    Type: Grant
    Filed: June 28, 2002
    Date of Patent: March 29, 2005
    Assignee: SK Telecom Co., Ltd.
    Inventor: Ha Jae Jeung
  • Publication number: 20040240476
    Abstract: Systems and techniques are disclosed wherein a gated pilot signal can be re-acquired faster by searching a last known pilot offset and/or searching a last coset in which the last pilot signal was found.
    Type: Application
    Filed: May 31, 2003
    Publication date: December 2, 2004
    Inventor: Abhay Arvind Joshi
  • Patent number: 6804264
    Abstract: Disclosed is a method of generating pilot sequences having double lengths of slots used for frame synchronization in an up or down link of a next generation mobile communication system which adopts W-CDMA mode. Disclosed is a method of generating pilot sequences having double lengths of slots used for frame synchronization and defined by 4l+2(l=1,2,3, . . . ) while providing a mathematical method of generating code sequences of slot length.
    Type: Grant
    Filed: March 14, 2000
    Date of Patent: October 12, 2004
    Assignee: LG Information & Communications, Ltd.
    Inventor: Young-Joon Song
  • Patent number: 6724778
    Abstract: A method and apparatus for long code generation in synchronous, multi-chip rate systems, wherein a first code sequence having a first bit rate, and a second code sequence having the first bit rate, the second code sequence being a time delay of the first code sequence, are multiplexed together, producing a desired long code.
    Type: Grant
    Filed: March 16, 2000
    Date of Patent: April 20, 2004
    Assignee: Motorola, Inc.
    Inventors: Kevin Michael Laird, Jiangnan Chen, Frank Fei Zhou
  • Patent number: 6721300
    Abstract: STTD encoding is signal processing carried out when a base station performs diversity transmission in open-loop mode to a mobile station. The STTD encoding method according to the present invention applies reverse STTD encoding on a pilot signal that should not be subjected to STTD encoding beforehand. Then, the multiplexer time-multiplexes the pilot signal with transmission data and control data to compose a transmission frame. Then, all data included in the transmission frame is subjected to STTD encoding. Applying reverse encoding before frame composition eliminates the need for distinguishing data to be encoded from data not to be encoded during STTD encoding.
    Type: Grant
    Filed: August 28, 2000
    Date of Patent: April 13, 2004
    Assignee: Matsushita Electric Industrial Co., LTD
    Inventors: Toru Akiba, Daisuke Yamada
  • Publication number: 20030223462
    Abstract: A method and an apparatus for implementing carrier suppressed data format on conventional OTDM modules is provided. Adaptive phase shifting of optical signals traversing one of the tributaries of an OTDM module is performed with feedback loop control. A tapped portion of the input carrier signal is phase modulated at a frequency fc, and is combined with a tapped portion of the output from the OTDM. A phase shifter controller fed with this combined signal photodetects and band-pass filters the signal around fc to extract the amplitude of the AC component of the envelope of the combined signal, which depends upon the phase difference between successive pulses of the OTDM output. This signal is used to control a phase shifter coupled along one of the tributaries of the OTDM to adjust the phase difference of the signals of the two tributaries so that carrier suppression results.
    Type: Application
    Filed: May 31, 2002
    Publication date: December 4, 2003
    Applicant: AR card
    Inventors: Xiaoli Fu, Genzao Zhang, Feng Shi, Tongqing Wang, Jinghui Li
  • Patent number: 6658050
    Abstract: A transceiver transmits signals with power control bits, the power control bits instructing the other transceiver to establish selected power levels for its return signal. In one form, a processor is adapted to determine channel coefficients for the pilot symbols as a function of both (1) the selected power levels of the other transceiver signal and (2) the difference between the predetermined pilot symbols and the pilot symbols as received by the receiver. The processor then interpolates channel coefficients for all symbols in the received signals based on the determined pilot symbol channel coefficients. In an alternate form, the processor uses a selected auto-correlation function which takes into account the selected power levels of the other transceiver signal to calculate an interpolation filter. In this alternate form, the processor then uses the calculated interpolation filter and channel coefficients for the pilot symbols to interpolate channel coefficients for symbols between the pilot symbols.
    Type: Grant
    Filed: September 11, 1998
    Date of Patent: December 2, 2003
    Assignee: Ericsson Inc.
    Inventors: Rajaram Ramesh, Yi-Pin Eric Wang
  • Patent number: 6621811
    Abstract: A method and system for producing a plurality of pilot beacon signals with different carrier frequencies is disclosed. One original pilot beacon signal is first obtained, and a splitter is used to make copies of the pilot beacon signal. Each of the copies are fed into a mixer for generating a plurality of intermediate signals with different frequencies. A bandpass filter is subsequently used to select a final one among the intermediate signals. Thus, a set of pilot beacon signals with different frequencies are successfully obtained.
    Type: Grant
    Filed: July 31, 1999
    Date of Patent: September 16, 2003
    Assignee: Nortel Networks Limited
    Inventors: Chu-Rui Chang, Meng Yee
  • Patent number: 6608843
    Abstract: In a digital communication system such as a mobile radio system, fading distortion is compensated with a raised precision. In a transmitter, pilot signals are regularly inserted in the information signals. The amplitude of the pilot signals are set larger than the maximum possible amplitude of the information signals. The modulation scheme of the pilot signals may be different from that of the information signals. In a receiver, the fading distortion of each of the pilot signals is determined. The fading distortions of the information signals are estimated by interpolation using the determined fading distortion of the pilot signal, and then compensated. The frequency band of each information signal is preferably limited with a roll-off filter with a roll-off coefficient ranging from 0.1 to 0.4.
    Type: Grant
    Filed: April 15, 1999
    Date of Patent: August 19, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yutaka Murakami, Masayuki Orihashi, Akihiko Matsuoka, Morikazu Sagawa
  • Patent number: 6606363
    Abstract: A method and apparatus estimate an offset between a carrier frequency of a transmitter and a local reference frequency of a receiver. A received signal is separated into frequency synchronization signals and data, and a determination is made whether the frequency synchronization signals are adequate for estimating the frequency offset. This determination may be made based on, e.g., an estimated Doppler spread, an estimated signal to noise ratio, and/or an available amount of frequency offset estimation time. The frequency offset is estimated based on the determination results. If the frequency synchronization signals are adequate for estimating the frequency offset, the frequency synchronization signals are used for determining the frequency offset. Otherwise, the rate of the frequency synchronization signals is increased, e.g., by using the data as frequency synchronization signals, in which case the data is combined with the frequency synchronization signals to determine the frequency offset.
    Type: Grant
    Filed: December 28, 1999
    Date of Patent: August 12, 2003
    Assignee: Telefonaktiebolaget LM Ericsson (Publ)
    Inventors: Roozbeh Atarius, Rajaram Ramesh
  • Publication number: 20030137996
    Abstract: Systems and techniques are disclosed detecting an embedded signal which includes producing a plurality of first correlated values from a portion of the first signal and a second signal, transforming the first correlation values into a plurality of second correlation values related to a frequency content of the first correlation values, and searching for the embedded signal by evaluating the second correlation values. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.
    Type: Application
    Filed: January 24, 2002
    Publication date: July 24, 2003
    Inventors: Mark Roh, Raghu Challa, Serguei A. Glazko
  • Patent number: 6590873
    Abstract: The invention is a method for controlling power on multiple forward link communication channels by using multiple power control sub-channels, wherein each power control sub-channel is associated with a forward link communication channel to be power controlled. A fundamental power control sub-channel and a supplemental power control sub-channel are time multiplexed onto a reverse pilot channel. Transmitted over the fundamental power control sub-channel is a fundamental power control bit for indicating to a base station to increase or decrease its transmission power over a corresponding forward fundamental channel. Transmitted over the supplemental power control sub-channel is a supplemental power control bit for indicating to a base station to increase or decrease its transmission power over a corresponding forward supplemental channel. The pilot sub-channels are preferably separated by the fundamental and supplemental power control sub-channels for time diversity purposes.
    Type: Grant
    Filed: February 5, 1999
    Date of Patent: July 8, 2003
    Assignee: Lucent Technologies Inc.
    Inventors: Quinn Li, Martin Howard Meyers, John Minkoff, Xiao Cheng Wu
  • Patent number: 6535502
    Abstract: The invention includes a method of inserting pilot symbols into communication signals in which a plurality of signals to be transmitted are generated; each signal is divided into frames and each frame consists of a plurality of blocks. A pilot signal block is inserted into each frame of each signal before transmission. The pilot signal blocks are inserted in a time staggered fashion, spread though out the frame. The pilot symbols are time-staggered using an arbitrary algorithm for the pilot symbol insertion. This enables each receiver to perform more accurate, continuous channel estimation and results in a reduced Bit Error Rate (BER) and an improved Quality of Service (QoS). A receiver according to the invention makes use of pilot symbols of all other users in the system in order to improve its channel estimation for user k and this gives more reliable data detection.
    Type: Grant
    Filed: June 23, 1999
    Date of Patent: March 18, 2003
    Assignee: Agere Systems Inc.
    Inventor: Stephan ten Brink
  • Patent number: 6493329
    Abstract: A method and circuit for adaptively estimating channel conditions of a pilot channel in a wireless communication system. The method includes estimating channel statistics of the pilot channel, and adaptively filtering the pilot channel in response to the estimated channel statistics. The estimation is performed by filtering a channel signal derived from the pilot channel to determine an estimated channel mean and an estimated channel covariance. In order to perform the adaptive filtering, the present invention partitions the pilot channel into one or more time slots and weights each time slot according to the channel statistics. Thus, an advantage of the present invention is that it automatically and continually updates the pilot filter parameters in order to optimize the pilot filter performance over a broad range of channel conditions.
    Type: Grant
    Filed: August 23, 1999
    Date of Patent: December 10, 2002
    Assignee: Qualcomm Incorporated
    Inventor: Gilbert Leung
  • Patent number: 6442218
    Abstract: The present invention relates to a demodulator which receives a signal transmitted via phase modulation or multivalue QAM modulation, and decides transmitted data based on the received signal. The present invention enhances a transmission-line estimate by using tentatively decided data symbols as pilot symbols and in estimating a transmission line without a decrease in accuracy of transmission-line estimate even when an error rate of the tentatively decided data symbols is increased. The demodulator includes a pilot-based transmission-line estimation unit for estimating transmission-line characteristics by using pilot symbols. A tentative-data-decision unit for tentatively deciding data symbols based on the pilot-based transmission-line estimate. A data-based transmission-line estimation unit for estimating the transmission-line characteristics by using the tentatively decided data.
    Type: Grant
    Filed: August 19, 1999
    Date of Patent: August 27, 2002
    Assignee: Fujitsu Limited
    Inventors: Michiharu Nakamura, Yasuyuki Oishi, Kazuo Nagatani, Hajime Hamada, Yoshihiko Asano, Hiroyuki Seki, Yoshinori Tanaka
  • Patent number: 6430200
    Abstract: An apparatus and method for generating a pilot signal for hard hand-off. A pilot signal generator of a base station for generating an identifying pilot signal corresponding to a target base station to perform inter-frequency hard hand-off in the code division multiple access cellular system comprises an intermediate frequency amplifier/divider, a service RF path unit and a RF path unit. The IF amplifier/divider divides the amplified IF signal transferred from a digital MODEM. The service RF path unit up-converts a first portion of the divided signal into a desired radio frequency and transmits the up-converted RF signal for actual communication and the RF path unit up-converts a second portion of the divided signal into a desired RF and transmits the up-converted RF signal as an identifying pilot signal corresponding to a target base station for a hard hand-off.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: August 6, 2002
    Assignee: Samsung Electronics, Co., Ltd.
    Inventors: Deog-Su Han, Dae-Sik Kim
  • Publication number: 20020048285
    Abstract: A method and device for translating telecommunication network Internet Protocol addresses by using a leaky-controlled memory. In substance, a hash computer and a memory with locations for the keys (or addresses) to be stored and corresponding locations for the updating date of the key memory location are used in combination. Should a memory address (a(j)) such that KEY=K[a(j)] be not found, a memory address corresponding to an instant and/or to an updating date elder that a certain value is occupied. In the inverse translation process, the selected address (a(j)) is received and the memory is accessed updating again the time information by inserting the current instant and/or date.
    Type: Application
    Filed: May 30, 2001
    Publication date: April 25, 2002
    Applicant: ALCATEL
    Inventors: Carlo Costantini, Marco Modena
  • Publication number: 20020048284
    Abstract: A high availability, high reliability storage system that leverages rapid advances in commodity computing devices and the robust nature of internetwork technology such as the Internet. A system of parity distribution in accordance with the present invention allows for greater fault tolerance and levels of storage efficiency than possible with conventional RAID (levels 0-5) paradigms. Data can be recovered or made available even in the case of loss of N, N+1, or more devices or storage elements over which stripes of the data set have been distributed or partitioned.
    Type: Application
    Filed: February 13, 2001
    Publication date: April 25, 2002
    Inventors: Gregory Hagan Moulton, Felix Hamilton
  • Publication number: 20020036999
    Abstract: A method for reducing multiple dominant pilots in a CDMA transmission system comprises linking a transceiver element with a nearby base station for transporting signals between the transceiver element and the nearby base station. Transmitting from the transceiver element forward link signals of a nearby sector associated with the nearby base station. An apparatus is also described.
    Type: Application
    Filed: November 21, 2001
    Publication date: March 28, 2002
    Inventors: Qi Bi, Wen-Yi Kuo, Martin Howard Meyers, Charles Albert Sanders, Carl Francis Weaver
  • Patent number: 6304563
    Abstract: The punctured pilot channel comprises information symbols of uncertain sign punctured into a sequence of pilot channel symbols of predetermined sign. The apparatus includes an information sign demodulation circuit for determining the sign of the information symbols in response to the pilot channel symbols. A continuous pilot generator generates a non-punctured pilot channel of predetermined sign from the information symbols and the pilot channel symbols. In a first embodiment, the information sign demodulator further comprises a dot product circuit for calculating a dot product of the pilot channel symbols and the punctured information symbols, and a threshold comparator for comparing the dot product to a predetermined threshold.
    Type: Grant
    Filed: April 23, 1999
    Date of Patent: October 16, 2001
    Assignee: Qualcomm Incorporated
    Inventors: Luca Blessent, Quaeed Motiwala
  • Patent number: 6269106
    Abstract: A method to provide information in a communication access network which includes a plurality of terminals (T12, T12, T13, . . . , T31, . . . ) and a head-end (HE). The head-end (HE) includes transceivers (TRX1, TRX2, TRX3, . . . ) and is downstream coupled to each one of the terminals via a downstream common link (Lc) and a tree-like distributive network. Each transceiver provides to a combiner (COMB) included in the head-end (HE) a downstream signal (Sd1, Sd2, Sd3, . . . ) in a frequency band (CH1, CH2, CH3, . . . ) associated to the transceivers (TRX1, TRX2, TRX3, . . . ). The downstream signals (Sd1, Sd2, Sd3, . . . ) are together combined into a downstream modulated signal (S-MOD) which is broadcasted from the head-end (HE) to the terminals. A first one (T12) of the terminals is upstream coupled to a first transceiver (TRX1) via an upstream link.
    Type: Grant
    Filed: July 7, 1998
    Date of Patent: July 31, 2001
    Assignee: Alcatel
    Inventors: Robert Peter Christina Wolters, Harry Franciscus Ludovica Vanhoof
  • Patent number: 6122334
    Abstract: A novel and improved apparatus for a wireless communication device, which provides fast detection and validation of pilot signals while minimizing the probability of false detection. In the apparatus a searcher subsystem generates a pilot energy sample corresponding to a pilot signal, which is provided to a pilot signal detection filter, comprising two parallel branches. The first branch calculates a weighted historical average of a signal strength of the pilot signal in response to the pilot energy sample, the second branch verifies the pilot energy sample in a state machine, wherein transitions of the state machine are proportional to a magnitude of the pilot energy sample. A pilot detection signal is generated if either the weighted historical average exceeds selected threshold, or a state of the state machine exceeds a maximum value of the states.
    Type: Grant
    Filed: June 10, 1997
    Date of Patent: September 19, 2000
    Inventor: Robbin D. Hughes
  • Patent number: 6108351
    Abstract: The process is characterized in that the pilot signals (10) generated upstream of the device (11) whose non-linearity it is desired to measure pass through a known non-linear device (15) delivering intermodulation products of known characteristics and in that at least one of the known intermodulation products is harnessed in order to modulate, with the aid of synchronous detection circuits (17), at least one of the signals relating to the components of the intermodulation products of the device to be measured.The applications pertain to the analog transmission of television signals over optical fibers.
    Type: Grant
    Filed: July 9, 1997
    Date of Patent: August 22, 2000
    Assignee: Thomson Broadcast Systems
    Inventors: Patrick Hardy, Stephane Hergault
  • Patent number: 5987023
    Abstract: In time domain multiplex/time domain multiple access communications between a base station and subscriber unit, the base station sends a timing reference signal. A subscriber unit responds with a data packet (a) sufficiently short to ensure correct reception by the base irrespective of transmission time. The base determines the transmission time taken and instructs the subscriber unit to advance its timings so that longer data packets (b) can be sent so as to be received when expected. The timing adjustment includes both a fixed present component dependent on approximate separation of base station and subscriber unit, and a second component from measurement of the transmission time taken.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: November 16, 1999
    Assignee: Ionica International, Limited
    Inventors: Richard John Albrow, Simon Alexander Black, Leigh Carter, Rupert Leslie Alexander Goodings, Paul Maxwell Martin, Neil Philip Piercy
  • Patent number: 5966402
    Abstract: A pilot signal detection method, a pilot signal detection apparatus and a subscriber in which the timing of a pilot signal of a neighbor base station is detected correctly and efficiently for improving the quality of communication of a mobile station. Partial correlation is taken of a pilot signal of an arbitrary base station within a first range of correlation. The pilot signal for which the result of the partial correlation has exceeded a first threshold becomes a pilot candidate signal for detection. Partial correlation is then taken of the pilot signal of the pilot candidate signal within a range of correlation broader than the first range of correlation. The pilot signal for which the result of the partial correlation has exceeded a second threshold becomes a pilot detection signal.
    Type: Grant
    Filed: November 18, 1996
    Date of Patent: October 12, 1999
    Assignee: Sony Corporation
    Inventor: Katsuya Yamamoto
  • Patent number: 5949794
    Abstract: The invention relates to a control signal for receivers, said control signal being formed by juxtaposing two signal elements of equal duration, and time symmetrical. For example, the signal comprises at least one first pseudo-random noise digital sequence s(N.sub.s -1) to s(0) and, periodically, at least one second digital sequence s(N.sub.s -1) to s(0), corresponding to the inverse, obtained by time symmetry, of said first sequence. The signal may be used in particular for performing time and frequency synchronization on receivers and/or for equalizing signals received by said receivers. The invention also relates to methods and apparatuses that use said signal.
    Type: Grant
    Filed: June 20, 1995
    Date of Patent: September 7, 1999
    Assignee: Alcatel Mobile Communication France
    Inventor: Alain Chiodini
  • Patent number: 5917811
    Abstract: In a communications network, a network user communicates using a remote unit with another user via at least one base station. The network is comprised of first and second mobile switching control stations respectively controlling communications through a first set of base stations including a first base station and through a second set of base stations including a second base station. To direct communications between the remote unit and the first and second base stations the first base station measures a round trip delay of an active communication signal between the first base station and the remote unit. The remote unit measures a first phase offset of a pilot signal received from a first candidate base station and reports it to the first mobile switching center via the first base station.
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: June 29, 1999
    Assignee: Qualcomm Incorporated
    Inventors: Lindsay A. Weaver, Jr., Toni Lee Holcman, David B. Munsinger, Noam A. Ziv, Kenneth R. Baker
  • Patent number: 5875208
    Abstract: In a discrete multitone spread spectrum system, a base station receives a transmission burst from a remote unit being installed that includes delay compensation pilot tones that are uniformly spread throughout the transmission bandwidth. The arrival time transmission burst is not synchronized with the other remote units transmitting to the base station. The base station measures the phase delay of each tone and calculates the delay of the remote unit from the slope of the line of phase angle versus tone frequency. The base station transmits a signal to the remote unit that includes the magnitude and direction of the delay, which allows the remote unit to adapt the timing of its transmission to be synchronized with the other remote units.
    Type: Grant
    Filed: February 24, 1997
    Date of Patent: February 23, 1999
    Assignee: AT&T Wireless Services, Inc
    Inventor: Elliott Hoole
  • Patent number: 5831752
    Abstract: A multi-bit packet carried on an optical network includes a marker pulse. A bit-rate clock for use in a bit-level operation on the packet is generated by replicating the marker pulse. The bit-level operation may comprise retiming, regeneration or demultiplexing. The marker pulse may be distinguished by a fixed, bit-asynchronous time relationship to the rest of the packet.
    Type: Grant
    Filed: December 24, 1996
    Date of Patent: November 3, 1998
    Assignee: British Telecommunications public limited company
    Inventors: David Cotter, Kevin Smith, Julian K. Lucek, David C. Rogers
  • Patent number: 5812542
    Abstract: A method (250) determines weighting coefficients (188, 190, 192) in a code division multiple access (CDMA) radio receiver (100). A representation (172) of a desired RF signal (166) is received (108, 124, 127). A plurality of data signals (176, 180, 184) are generated responsive to the representation (172) of a desired RF signal (166). A plurality of pilot signals (178, 182, 186) are generated responsive to the first representation (172) of a desired RF signal (166). A total received signal power (174) is measured (128). A plurality of weighting coefficients (188, 190, 192) are determined responsive to the plurality of data signals (176, 180, 184), the plurality of pilot signals (178, 182, 186) and the total received signal power (174).
    Type: Grant
    Filed: March 18, 1996
    Date of Patent: September 22, 1998
    Assignee: Motorola, Inc.
    Inventors: Eugene J. Bruckert, Fuyun Ling
  • Patent number: 5809083
    Abstract: A system and method for transmitting digital data over a wireless channel uses periodically-transmitted, differentially encoded pilot words to allow a receiver to rapidly synchronize with a transmitter. Each differentially encoded pilot word comprises at least two pilot symbols that are separated by a fixed difference. The receiver monitors differences between symbols to locate the differentially encoded pilot words, and to thereby become synchronized with the transmitter. Once the receiver becomes synchronized with the transmitter, the receiver uses the pilot symbols of the differentially encoded pilot words to perform channel estimation and compensation.
    Type: Grant
    Filed: November 23, 1994
    Date of Patent: September 15, 1998
    Assignee: AT&T Wireless Services, Inc.
    Inventor: Andrew S. Wright
  • Patent number: 5757854
    Abstract: A system for combining AM and FM transmissions. In-band, On-channel, FM Digital Audio Broadcast (IBOC FM-DAB) allows simultaneous transmission of DAB and FM over existing FM allocations without interfering with conventional analog FM signals. The utility of existing FM spectrum allocations is therefore enhanced.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: May 26, 1998
    Assignee: USA Digital Radio Partners, L.P.
    Inventors: Billie J. Hunsinger, A J. Vigil, Leland P. Solie
  • Patent number: 5726982
    Abstract: A method and an apparatus for searching code division multiple access pilot signal energies includes limiting a pilot signal window size above a lower limit and only analyzing search result data corresponding to an instructed pilot signal window size. A central processing unit instructs a searcher receiver within a mobile station modem application specific integrated circuit to search for pilot signal energies within an instructed pilot signal search window unless the instructed pilot signal window size is smaller than a pilot signal window size lower limit. In such a case, the pilot signal search window size is artificially designated as the pilot signal window size lower limit to prevent excessive search completion interrupts from over utilizing central processing unit resources.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: March 10, 1998
    Assignee: OKI Telecom
    Inventor: Robert C. Witter