US Patent No: 6,263,013

Number of patents in Portfolio can not be more than 2000

Fast tracking of PN synchronization in a direct-sequence spread-spectrum digital communications system

1 Status Updates

Stats

See full text
ATTORNEY / AGENT: (SPONSORED)

Importance

Loading Importance Indicators... loading....

Abstract

See full text

In a direct sequence spread spectrum communication receiver, a system and method for recovering the timing of a pseudo-random noise (PN) sequence used for despreading the received signals. In one embodiment of the method, the receiver waits for detection of a SYNC field to confirm at least a coarse synchronization or the receiver's local PN sequence with the received PN sequence (in the received signal). The receiver then performs a fast tracking to finely synchronize the receiver's PN sequence with the received PN sequence, preferably for a fixed duration of time. One embodiment of a system for performing the synchronization with the fast tracking includes an input for receiving a received spread-spectrum data stream, an ML detection logic, a receiver PN clock, a despreading mixer that generates a narrowband signal from the spread-spectrum data stream, a testing logic that generates a PASS output if it identifies a SYNC field in the narrowband signal, and a fast-tracking logic. The fast-tracking logic temporarily advances and temporarily delays the receiver PN clock by a small shift and measures the resulting correlations between the receiver's PN sequence and the received PN sequence. If the advanced correlation is greater or less than the delayed correlation, then the fast-tracking logic accordingly makes a small adjustment to advance or delay the receiver PN clock. This temporary advancing, temporary delaying, and adjusting of the receiver PN clock is preferably repeated a fixed number of times.

Loading the Abstract Image... loading....

First Claim

See full text

all claims..

Related Publications

Loading Related Publications... loading....

Patent Owner(s)

Patent OwnerAddressTotal Patents
DSP GROUP INC.SANTA CLARA, CA45

International Classification(s)

  • [Classification Symbol]
  • [Patents Count]

Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Hendrickson, Alan F Austin, TX 39 504

Cited Art Landscape

Patent Info (Count) # Cites Year
 
DSP GROUP INC. (2)
6,002,709 Verification of PN synchronization in a direct-sequence spread-spectrum digital communications system 54 1998
6,002,710 Timing recovery for a pseudo-random noise sequence in a direct-sequence spread-spectrum communications system 17 1998
 
NOKIA MOBILE PHONES LTD. (2)
5,440,597 Double dwell maximum likelihood acquisition system with continuous decision making for CDMA and direct spread spectrum system 106 1993
5,642,377 Serial search acquisition system with adaptive threshold and optimal decision for spread spectrum systems 112 1995
 
AIRSPAN NETWORKS INC. (1)
5,696,766 Apparatus and method of synchronizing a transmitter in a subscriber terminal of a wireless telecommunications system 28 1995
 
AT&T Bell Laboratories (1)
5,361,276 All digital maximum likelihood based spread spectrum receiver 147 1993
 
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. (1)
5,689,525 Direct-sequence spread-spectrum communication system 22 1995
 
WI-LAN INC. (1)
5,745,496 Apparatus and method of establishing a downlink communication path in a wireless telecommunications system 12 1995
 
Other [Check patent profile for assignment information] (1)
4,279,018 PN Lock indicator for dithered PN code tracking loop 54 1979

Patent Citation Ranking

Forward Cite Landscape

Patent Info (Count) # Cites Year
 
INTEL CORPORATION (18)
6,965,778 Maintenance of channel usage in a wireless communication system 3 1999
7,079,523 Maintenance link using active/standby request channels 21 2001
8,175,120 Minimal maintenance link to support synchronization 0 2001
7,936,728 System and method for maintaining timing of synchronization messages over a reverse link of a CDMA wireless communication system 0 2001
8,155,096 Antenna control system and method 0 2001
7,551,663 Use of correlation combination to achieve channel detection 3 2002
6,940,842 System and method for maintaining wireless channels over a reverse link of a CDMA wireless communication system 20 2004
6,928,064 Fast acquisition of traffic channels for a highly variable data rate reverse link of a CDMA wireless communication system 3 2004
7,773,566 System and method for maintaining timing of synchronization messages over a reverse link of a CDMA wireless communication system 0 2004
7,480,280 Fast acquisition of traffic channels for a highly variable data rate reverse link of a CDMA wireless communication system 2 2005
8,045,990 Maintenance of channel usage in a wireless communication system 0 2005
8,134,980 Transmittal of heartbeat signal at a lower level than heartbeat request 2 2007
8,274,954 Alternate channel for carrying selected message types 0 2009
8,139,546 System and method for maintaining wireless channels over a reverse link of a CDMA wireless communication system 0 2010
8,638,877 Methods, apparatuses and systems for selective transmission of traffic data using orthogonal sequences 0 2011
8,509,268 Minimal maintenance link to support sychronization 0 2011
8,437,330 Antenna control system and method 0 2012
8,687,606 Alternate channel for carrying selected message types 0 2012
 
INTERDIGITAL TECHNOLOGY CORPORATION (4)
7,496,072 System and method for controlling signal strength over a reverse link of a CDMA wireless communication system 1 2001
7,394,791 Multi-detection of heartbeat to reduce error probability 13 2002
7,221,664 Transmittal of heartbeat signal at a lower level than heartbeat request 14 2002
7,746,830 System and method for maintaining wireless channels over a reverse link of a CDMA wireless communication system 0 2005
 
MITSUBISHI DENKI KABUSHIKI KAISHA (2)
7,130,353 Multiuser detection method and device 3 2001
7,349,459 Multiuser detection method and device in DS-CDMA mode 0 2001
 
ADVANTEST CORPORATION (1)
8,081,694 Device, method, and program for signal analysis, and recording medium 0 2007
 
InterDigital Corporation (1)
7,602,749 Fast acquisition of traffic channels for a highly variable data rate reverse link of a CDMA wireless communication system 2 2002
 
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. (1)
6,700,921 Spread-spectrum communication apparatus 3 2000
 
SK TELECOM CO., LTD. (1)
7,012,948 Method for assigning codes in uplink of synchronous wireless telecommunication system 3 2001
 
SONY CORPORATION (1)
7,936,712 Signal processing apparatus, signal processing method, and program 0 2007
 
THOMSON LICENSING (1)
6,795,490 Signal detection in a direct-sequence spread spectrum transmission system 5 2002
 
Other [Check patent profile for assignment information] (1)
7,949,032 Methods and apparatus for masking and securing communications transmissions 17 2006