Subscriber unit for performing an access procedure

• US 7,873,328 B2
• Filed: 05/07/2008
• Issued: 01/18/2011
• 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): Le; Lana N
• Application Number:
  US12/116,262
• Publication Number:
  US 20080240046A1
• Time in Patent Office: 986 Days
• Field of Search: 455/522, 455/69, 455 6711- 6716, 4552261-2264, 370/335, 370/342, 370/441, 370/310, 370/330, 370336-337, 370/345, 370/347, 370/350, 370/311, 370/474, 375145-147, 375/140, 375354-356, 375/365
• US Class Current: 455/69
• 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 base station for controlling transmission power during the establishment of a communication channel utilizes the reception of a short code during initial power ramp-up. The short code is a sequence for detection by the base station which has a much shorter period than a conventional access code. The ramp-up starts from a power level that is lower than the required power level for detection by the base station. The power of the short code is quickly increased until the signal is detected by the base station. Once the base station detects the short code, it transmits an indication that the short code has been detected.

Claims

1. A subscriber unit for use in a wireless network, comprising:

a transmitter configured to transmit, when the subscriber unit is attempting to first access the wireless network, a first set of transmission bits;

a receiver configured to receive a first indication indicating that the first set of transmission bits has been detected;

wherein the transmitter is further configured to transmit, in response to the received first indication, a second set of transmission bits;

wherein the transmitter is further configured to transmit, in response to not receiving the first indication, a third set of transmission bits wherein the third set of transmission bits is different than the first set of transmission bits;

wherein the transmitter is further configured to transmit, subsequent to the transmitting of the second set of transmission bits, a fourth set of transmission bits; and

wherein the subscriber unit is further configured to facilitate closed loop power control with respect to the fourth set of transmission bits.

2. The subscriber unit of claim 1 wherein the receiver is further configured to receive a second indication indicating that the second set of transmission bits was detected;

and wherein the transmitter transmits the fourth set of transmission bits on a condition that the second indication is received by the receiver.

3. The subscriber unit of claim 1 wherein the first set, second set and third set of transmission bits are not closed loop power controlled.

4. The wireless subscriber unit of claim 1 wherein the first and third set of transmission bits are chosen to be one of a plurality of predetermined lengths.

5. A wireless subscriber unit comprising:

a transmitter configured to send a first transmission derived using a first sequence to access a network and, on a condition that a first indication indicating that the first transmission was detected is not received by the subscriber unit, to transmit a second transmission derived using a second sequence;

wherein the transmitter is further configured to send, in response to the subscriber unit receiving the first indication, a third transmission, wherein the first and second transmissions are not closed loop power controlled; and

wherein the transmitter is further configured to send, subsequent to sending the third transmission, a fourth transmission that is closed loop power controlled.

6. The wireless subscriber unit of claim 5 wherein the first and second transmissions are chosen to be one of a plurality of predetermined lengths.

7. The wireless subscriber unit of claim 5 further configured to receive a second indication indicating that the third transmission was detected.

8. The wireless subscriber unit of claim 7 wherein the fourth transmission is sent subsequent to receipt of the second indication.

9. A wireless subscriber unit comprising:

a transmitter configured to send a first transmission to access a network and, on a condition that a first indication indicating that the first transmission was detected is not received by the subscriber unit, to transmit a second transmission;

wherein the transmitter is further configured to send, in response to the subscriber unit receiving the first indication, a third transmission, wherein the first and second transmissions are not closed loop power controlled; and

wherein the transmitter is further configured to send, subsequent to sending the third transmission, a fourth transmission that is closed loop power controlled.

10. The wireless subscriber unit of claim 9 wherein the first and second transmissions are chosen to be one of a plurality of predetermined lengths.

11. The wireless subscriber unit of claim 9 further configured to receive a second indication indicating that the third transmission was detected.

12. The wireless subscriber unit of claim 11 wherein the fourth transmission is sent subsequent to receipt of the second indication.