Initial power control for spread-spectrum communications

• US 7,123,600 B2
• Filed: 02/28/2001
• Issued: 10/17/2006
• Est. Priority Date: 06/30/1995
• 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., Kowalski, John
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Fox, Jamal A.
• Application Number:
  US09/795,540
• Publication Number:
  US 20020036996A1
• Time in Patent Office: 2,057 Days
• Field of Search: 370/335, 370/310, 370/318, 370/320, 370/328, 370/329, 370/342, 370/465, 370/468, 370/477, 370/441, 370/479, 370/503, 370/515, 370/203, 370/208, 370/209, 375/140, 375/146, 375/147, 375/354, 375/367, 375/208, 375/200, 375/206, 375/362, 375/365, 455/31.1, 455/33.1, 455/38.1, 455/53.1, 455/54.1, 455/67.1, 455/226.1, 455/422, 455/507, 455/517, 455/522, 455/69
• US Class Current: 370/335
• CPC Class Codes: H03H 17/0226 comprising look-up tables
• CPC Class Codes: H03H 17/0254 Matched filters
• CPC Class Codes: H03H 17/06 Non-recursive filters
• CPC Class Codes: H03H 17/0607 comprising a ROM addressed by the input data signals
• CPC Class Codes: H03H 2218/06 Multiple-input, multiple-output [MIMO]; Multiple-input, single-output [MISO]
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 1/70753 Partial phase search
• CPC Class Codes: H04B 1/70754 Setting of search window, i.e. range of code offsets to be searched H04B1/70758 takes precedence
• 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 1/7077 Multi-step acquisition, e.g. multi-dwell, coarse-fine or validation
• 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 13/00 : Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04J 13/004 : Orthogonal
• CPC Class Codes: H04J 13/0077 : Multicode, e.g. multiple codes assigned to one user
• CPC Class Codes: H04L 1/0059 : Convolutional codes
• CPC Class Codes: H04L 1/1692 : Physical properties of the supervisory signal, e.g. acknowledgement by energy bursts
• CPC Class Codes: H04L 2001/0094 : Bus
• 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: H04N 1/00912 : Arrangements for controlling a still picture apparatus or components thereof not otherwise provided for
• CPC Class Codes: H04N 1/3333 : during transmission, input or output of the picture signal; within a single document or page
• CPC Class Codes: H04N 2201/3335 : Speed or rate
• 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 52/362 : Aspects of the step size
• 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

Abstract

A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station, and a plurality of subscriber units. The signals transmitted between the base station and subscriber unit use spread-spectrum modulation. The system and method transmits from the base station, a synchronization channel having a chip-sequence signal used by the plurality of subscriber units for synchronization. A first subscriber unit receives the synchronization channel, and determines timing from the synchronization channel. In order to initiate communications with the base station, the first subscriber unit transmits an access signal. The access signal has a plurality of power levels, which typically ramp up. The base station receives the access signal at a particular-power level. The base station then transmits to the first subscriber unit an acknowledgment signal. The first subscriber unit receives the acknowledgment signal, and transmits to the base station, a spread-spectrum signal.

Claims

1. A method using a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station, and a plurality of subscriber units, the method comprising the steps of:

transmitting, using spread-spectrum modulation, from said base station, a synchronization channel having a chip-sequence signal used for synchronization by the plurality of subscriber units;

receiving at a first subscriber unit of the plurality of subscriber units the synchronization channel;

acquiring, at said first subscriber unit, the synchronization channel;

synchronizing, at said first subscriber unit, to the synchronization channel;

determining, at said first subscriber unit, timing from the synchronization channel;

transmitting, using spread-spectrum modulation synchronized to the timing from the synchronization channel, from said first subscriber unit, an access signal, the access signal having a plurality of power levels;

detecting, at said base station, the access signal at a particular power level of the plurality of power levels;

transmitting, using spread-spectrum modulation, from said base station to said first subscriber unit, responsive to detecting the access signal, an acknowledgment signal;

receiving at said first subscriber unit the acknowledgment signal; and

transmitting, in response to receiving the acknowledgment signal, using spread-spectrum modulation, from said first subscriber unit to said base station, a spread-spectrum signal with data.

2. The method as set forth in claim 1 with the step of transmitting from the first subscriber unit the access signal, including the step of transmitting the access signal with the plurality of power levels ramping up, respectively.

3. A code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station and a plurality of subscriber units, the system comprising:

said base station for transmitting, using spread-spectrum modulation, a synchronization channel having a chip-sequence signal used for synchronization by the plurality of subscriber units;

a first subscriber unit of the plurality of subscriber units, for receiving the synchronization channel, for acquiring and synchronizing to the synchronization channel, and for determining timing from the synchronization channel;

said first subscriber unit for transmitting, using spread-spectrum modulation synchronized to the timing from the synchronization channel, an access signal, the access signal having a plurality of power levels;

said base station for detecting the access signal at a particular power level of said plurality of power levels;

said base station, in response to detecting the access signal, for transmitting, using spread-spectrum modulation, to said first subscriber unit, an acknowledgment signal;

said first subscriber unit for receiving the acknowledgment signal; and

said first subscriber unit, in response to receiving the acknowledgment signal, for transmitting, using spread-spectrum modulation, to said base station, a spread-spectrum signal with data.

4. The system as set forth in claim 3 with said first subscriber unit transmitting the access signal with the plurality of power levels ramping up, respectively.

5. A method using a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station, and a plurality of subscriber units, the method comprising the steps of:

transmitting, using spread-spectrum modulation, from said base station, a synchronization channel having a chip-sequence signal used for synchronization by the plurality of subscriber units;

receiving at a first subscriber unit of the plurality of subscriber units the synchronization channel;

determining, at said first subscriber unit, timing from the synchronization channel;

transmitting, using spread-spectrum modulation, from said first subscriber unit, an access signal, the access signal having a plurality of power levels;

detecting at said base station, the access signal at a particular power level of the plurality of power levels;

transmitting, using spread-spectrum modulation, from said base station to said first subscriber unit, responsive to detecting the access signal, an acknowledgment signal;

receiving at said first subscriber unit the acknowledgment signal; and

transmitting, in response to receiving the acknowledgment signal, using spread-spectrum modulation, from said first subscriber unit to said base station, a spread-spectrum signal with data.

6. The method as set forth in claim 5 with the step of transmitting from the first subscriber unit the access signal, including the step of transmitting the access signal with the plurality of power levels ramping up, respectively.

7. A code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station and a plurality of subscriber units, the system comprising:

said base station for transmitting, using spread-spectrum modulation, a synchronization channel having a chip-sequence signal used for synchronization by the plurality of subscriber units;

a first subscriber unit of the plurality of subscriber units, for receiving the synchronization channel, and for determining timing from the synchronization channel;

said first subscriber unit for transmitting, using spread-spectrum modulation, an access signal, the access signal having a plurality of power levels, respectively;

said base station for detecting the access signal at a particular power level of the plurality of power levels;

said base station, in response to detecting the access signal, for transmitting, using spread-spectrum modulation, to said first subscriber unit, an acknowledgment signal;

said first subscriber unit for receiving the acknowledgment signal; and

said first subscriber unit, in response to receiving the acknowledgment signal, for transmitting, using spread-spectrum modulation, to said base station, a spread-spectrum signal with data.

8. The system as set forth in claim 7 with said first subscriber unit transmitting the access signal with the plurality of power levels ramping up, respectively.

9. A code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station and a plurality of subscriber units, the system comprising:

means for transmitting from said base station, using spread-spectrum modulation, a synchronization channel having a chip-sequence signal used for synchronization by the plurality of subscriber units;

means for receiving at a first subscriber station of said plurality of subscriber units the synchronization channel, and for determining timing from the synchronization channel;

means for transmitting from said first subscriber station, using spread-spectrum modulation, an access signal, the access signal having a plurality of power levels;

means for detecting at said base station the access signal at a particular power level;

means for transmitting from said base station, in response to detecting the access signal, using spread-spectrum modulation, to said first subscriber means, an acknowledgment signal;

said first subscriber means for receiving the acknowledgment signal; and

said first subscriber means, in response to receiving the acknowledgment signal, for transmitting, using spread-spectrum modulation, to said base means, a spread-spectrum signal with data.

10. The system as set forth in claim 9 with said means for transmitting the access signal with the plurality of power levels ramping up, respectively.