Reverse link initial power setting using effective radiated power message to compute path loss

• US 20030060224A1
• Filed: 02/23/2001
• Published: 03/27/2003
• Est. Priority Date: 02/23/2000
• Status: Abandoned Application

• Current Assignee: IPR Licensing Incorporated (InterDigital, Inc.)
• Original Assignee: Tantivy Communications Incorporated (InterDigital, Inc.)
• Inventors: Proctor, James A. Jr., Rouphael, Antoine J., Hoffmann, John E., Nelson, George R. Jr.
• Application Number:
  US09/792,870
• Publication Number:
  US 20030060224A1
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 47/26 using explicit feedback to the source, e.g. choke packets
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 52/228 using past power values or information
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 74/0825 with collision detection
• CPC Class Codes: H04W 74/0858 collision detection
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

In an illustrative embodiment of the present invention, a reference signal including pilot information is transmitted from a base station to one or multiple field units over a pilot channel. A message is also sent to the field units over a paging channel to indicate an effective radiated power level at which the reference signal is transmitted on the pilot channel. Based on a received power level of the reference signal at a field unit and the effective radiated power level of the reference signal, a forward path loss is estimated at the field unit for the forward link between the base station and field unit. Assuming the path loss in the reverse link is approximately the same as the estimated forward link path loss, the field unit can transmit a reply message in the reverse link so that the base station generally receives a message at a desired power level.

Claims

1. A method for supporting wireless communications, the method comprising the steps of:

transmitting a first message from a first transceiver, the first message including effective radiated power level information at which the first transceiver transmits a reference signal; and

measuring a received power level of the reference signal received at a second transceiver;

decoding the first message at the second transceiver to determine the effective radiated power level information; and

estimating a path loss between the first and second transceivers by comparing the received power level and the effective radiated power level information.

2. A method in claim 1 further comprising the step of:

transmitting a second message from the first transceiver to the second transceiver indicating a desired power level at which subsequent messages shall be received at the first transceiver.

3. A method in claim 2 further comprising the step of:

transmitting a reply message from the second transceiver to the first transceiver at a power level so that the first transceiver receives the reply message at the desired power level.

4. A method as in claim 2 further comprising the step of:

determining a power output setting at the second transceiver based on an estimated path loss so that a message is received at the first transceiver at the desired power level.

5. A method as in claim 1, wherein the first message is transmitted over a paging channel of a CDMA (Code Division Multiple Access) communication system.

6. A method as in claim 3, wherein the reply message is transmitted over an access channel of a CDMA communication system.

7. A method as in claim 1, wherein the second transceiver transmits an access request message to the first transceiver in a time slot of an allocated reverse channel.

8. A method as in claim 7, wherein the access request message from the second transceiver to the first transceiver includes encoded information for measuring timing alignment of the second transceiver.

9. A method as in claim 1, wherein the second transceiver sends a reply message to the first transceiver, the reply message including a reference marker that is monitored for timing alignment.

10. A method as in claim 1, wherein the first transceiver transmits the first message over a dedicated channel to multiple transceivers.

11. A method as in claim 1 further comprising the step of:

measuring a power level at which a reply message transmitted from the second transceiver is received at the first transceiver.

12. A method in claim 11 further comprising the steps of:

comparing a power level at which the reply message is received at the first transceiver with a desired power level at which messages should be received; and

transmitting a power adjustment message to the second transceiver for subsequent message transmissions.

13. A method as in claim 1, wherein the reference signal includes pilot symbols.

14. A method as in claim 1, wherein the reference signal is transmitted over a pilot channel.

15. A method as in claim 1, wherein a path loss is calculated based on the difference between an effective radiated power level of the reference signal and power level of one or multiple received reference signals.