Method employed by a subscriber unit for controlling initial power ramp-up using short codes

• US 6,879,841 B2
• Filed: 03/01/2002
• Issued: 04/12/2005
• Est. Priority Date: 06/27/1996
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Lomp, Gary R., Ozluturk, Fatih M.
• Primary Examiner(s): Beamer, Temica M.
• Application Number:
  US10/086,330
• Publication Number:
  US 20020082040A1
• Time in Patent Office: 1,138 Days
• Field of Search: 455/522, 455/67.11, 455/69, 455/226.1, 455/115.1, 455/70, 455/436, 455/437, 370/335, 370/318, 370/320, 370/324
• US Class Current: 455/522
• 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 1/70755 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 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 2201/7071 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: 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 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 52/60 using different transmission rates for TPC commands

Abstract

A method employed by a subscriber station for controlling transmission power during the establishment of a communication channel utilizes the transmission of a short code from a subscriber unit during initial power ramp-up. The short code is a sequence which has a much shorter period than a conventional access code. The ramp-up starts from a low initial power level, and the power is quickly increased while repeatedly transmitting the short code until the subscriber unit receives an indication that the short code has been detected.

Claims

1. A method for operating a subscriber unit to regulate transmission power comprising:

transmitting a periodic signal at an initial predetermined power level wherein said initial predetermined power level is lower than a power level required for detection by a base station;

repeatedly transmitting the periodic signal, each transmission occurring at successively higher power levels;

receiving a confirmation signal at a specific power level which is based, in part, upon said periodic signal;

terminating transmission of the periodic signal and maintaining a power level present at a time that the confirmation signal is received at said subscriber unit; and

transmitting an access signal at the maintained power level, wherein the access signal includes an access code and the periodic signal includes a short code which is shorter than the access code.

2. The method of claim 1 wherein said short code has a period of one symbol.

3. The method of claim 1 wherein said subscriber unit periodically modifies the short code.

4. A method for operating a subscriber unit for regulating transmission power comprising:

transmitting a periodic signal at an initial predetermined power level wherein said initial predetermined power level is lower than a power level required for detection by a base station;

repeatedly retransmitting said periodic signal, each retransmission occurring at successively higher power levels;

maintaining a power level present upon receipt of a confirmation signal; and

transmitting an access signal at the maintained power level, the access signal including an access code, wherein the periodic signal is a short code which is shorter than the access code.

5. The method of claim 4 wherein said short code is an integer multiple of said access code.

6. The method of claim 4 wherein said short code is modified periodically.

7. The method of claim 4 wherein said short code has a period of one symbol.