System for using rapid acquisition spreading codes for spread-spectrum communications

• US 7,020,111 B2
• Filed: 12/21/2000
• Issued: 03/28/2006
• Est. Priority Date: 06/27/1996
• Status: Expired due to Term

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Lomp, Gary R., Ozluturk, Fatih M.
• Primary Examiner(s): Ton, Dang T
• Application Number:
  US09/742,990
• Publication Number:
  US 20020021686A1
• Time in Patent Office: 1,923 Days
• Field of Search: 370/335, 370/310, 370/311, 370/312, 370/314, 370/320, 370/331, 370/332, 370/333, 370/337, 370/345, 370/351, 370/350, 370/318, 370/317, 370/319, 370/321, 370/324, 370/344, 370/343, 370/503, 370/441, 370/442, 370/479, 370/480, 370/519, 370/518, 370/517, 370/512, 370/509, 370/505, 370/504, 370/506, 370/508, 455/503, 455/502, 455/422.1, 375/140, 375/146, 375/147, 375/354, 375/356
• US Class Current: 370/335
• CPC Class Codes: G06F 13/374 using a self-select method with individual priority code comparator
• CPC Class Codes: H03H 17/0226 comprising look-up tables
• CPC Class Codes: H03H 17/06 Non-recursive filters
• CPC Class Codes: H03H 21/0018 Matched filters
• CPC Class Codes: H03H 2218/06 Multiple-input, multiple-output [MIMO]; Multiple-input, single-output [MISO]
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 1/70752 Partial correlation
• CPC Class Codes: H04B 1/70753 Partial phase search
• CPC Class Codes: H04B 1/70755 Setting of lock conditions, e.g. threshold
• CPC Class Codes: H04B 1/70758 Multimode search, i.e. using multiple search strategies
• CPC Class Codes: H04B 1/708 Parallel implementation
• CPC Class Codes: H04B 1/7085 using a code tracking loop, e.g. a delay-locked loop
• CPC Class Codes: H04B 1/7093 Matched filter type
• CPC Class Codes: H04B 1/7115 Constructive combining of multi-path signals, i.e. RAKE receivers
• CPC Class Codes: H04B 1/712 Weighting of fingers for combining, e.g. amplitude control or phase rotation using an inner loop
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/70702 Intercell-related aspects
• CPC Class Codes: H04B 2201/70703 using multiple or variable rates
• CPC Class Codes: H04B 2201/70707 Efficiency-related aspects
• CPC Class Codes: H04B 2201/7071 with dynamic control of receiver resources
• CPC Class Codes: H04B 7/2628 : using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence
• CPC Class Codes: H04B 7/2637 : for logical channel control
• CPC Class Codes: H04B 7/264 : for data rate control
• CPC Class Codes: H04J 13/004 : Orthogonal
• CPC Class Codes: H04J 13/10 : Code generation
• CPC Class Codes: H04J 13/107 : by concatenation
• CPC Class Codes: H04L 1/004 : by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 2027/003 : at baseband only
• CPC Class Codes: H04L 2027/0053 : Closed loops
• CPC Class Codes: H04L 25/0212 : of impulse response
• CPC Class Codes: H04L 27/206 : using a pair of orthogonal carriers, e.g. quadrature carriers
• CPC Class Codes: H04L 27/2332 : using a non-coherent carrier
• CPC Class Codes: H04L 5/1446 : of transmission speed
• CPC Class Codes: H04W 52/08 : Closed loop power control
• CPC Class Codes: H04W 52/146 : Uplink power control
• CPC Class Codes: H04W 52/24 : using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/26 : using transmission rate or quality of service QoS [Quality of Service]
• CPC Class Codes: H04W 52/322 : Power control of broadcast channels
• CPC Class Codes: H04W 52/325 : Power control of control or pilot channels
• CPC Class Codes: H04W 52/343 : taking into account loading or congestion level
• CPC Class Codes: H04W 52/36 : with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/367 : Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/44 : in connection with interruption of transmission
• CPC Class Codes: H04W 52/50 : at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 52/52 : using AGC [Automatic Gain Control] circuits or amplifiers
• CPC Class Codes: H04W 52/54 : Signalisation aspects of the TPC commands, e.g. frame structure
• CPC Class Codes: H04W 52/60 : using different transmission rates for TPC commands
• CPC Class Codes: Y02D 10/00 : Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A system for rapidly acquiring a spreading code, used in a code division multiple access (CDMA) system comprises a generator for generating a first long code and a second long code, with each long code having a length of N chips. The first long code is different from the second long code. A transmitter transmits the first long code and the second long code at a first phase angle and at a second phase angle, respectively, on a carrier signal over a communications channel using radio waves. The first long code and the second long code may be transmitted at an in-phase (I) angle and at a quadrature-phase (Q) angle, respectively, on the carrier signal. From the communications channel, an I acquisition circuit and a Q acquisition circuit may acquire, in parallel, the first long code and the second long code from the I angle and the Q angle, respectively, of the carrier signal by searching, in parallel, N/2 chips of the first long code and the second long code.

Claims

1. A system for rapidly acquiring a spreading code used in a code division multiple access (CDMA) system, comprising:

a code generator for generating a plurality of P long codes, where P is a number of long codes in the plurality of long codes, with each long code having a length N chips, with each long code different from the other long codes in the plurality of long codes;

a transmitter, coupled to said code generator, for transmitting, over a communications channel using radio waves, the plurality of long codes at a plurality of phase angles, respectively, on a carrier signal, with each phase angle in the plurality of phase angles different from other phase angles in the plurality of phase angles; and

an acquisition circuit, coupled to the communications channel, for acquiring from the communications channel using said phase-acquisition circuit, the plurality of long codes, respectively, by searching, in parallel, N/P chips of each long code of the plurality of long codes.

2. The system as set forth in claim 1, wherein said acquisition circuit acquires from the communications channel using the phase-acquisition circuit, the plurality of long codes from the plurality of phase angles, respectively, of the carrier signal by searching, in parallel, N/P chips of each of the plurality of long codes.

3. The system of claim 2 wherein said transmitter transmits the plurality of long codes at the plurality of phase angles, respectively, on the carrier signal, with each phase angle in the plurality of phase angles representing an M-ary phase scheme.

4. The system of claim 3, wherein said acquisition circuit acquires from the communications channel using the phase-acquisition circuit, the plurality of long codes, respectively, of the carrier signal by searching, in parallel, N/P chips of a first long code and a second long code.

5. The system of claim 1, wherein said generator generates the plurality of long codes from a multiplicity of short codes, with each short code different from other short codes and each short code having a length less than N chips, with a first short code thereby embedded in a first long code and a second short code embedded in a second long code.

6. The system of claim 5, wherein said acquisition circuit acquires, from the communications channel using the phase-acquisition circuit the first short code embedded in the first long code and the second short code embedded in the second long code, from the first phase angle and the second phase angle, respectively, by searching, in parallel, N/P chips of the first short code and the second short code.