Qualifying available reverse link coding rates from access channel power setting

• US 20060088021A1
• Filed: 12/06/2005
• Published: 04/27/2006
• Est. Priority Date: 02/23/2001
• Status: Active Grant

• Current Assignee: Antoine J. Rouphael, George Rodney Jr. Nelson, James A. Proctor Jr, John E. Hoffmann
• Original Assignee: Antoine J. Rouphael, George Rodney Jr. Nelson, James A. Proctor Jr, John E. Hoffmann
• Inventors: Proctor, James A. Jr., Rouphael, Antoine J., Hoffmann, John E., Nelson, George Rodney Jr.
• Granted Patent: US 8,811,367 B2
• Time in Patent Office: Days
• US Class Current: 370/342
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04J 13/0003 Code application, i.e. aspects relating to how codes are applied to form multiplexed channels
• CPC Class Codes: H04L 5/22 using time-division multiplexing
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• 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 52/365 Power headroom reporting
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0466 the resource being a scrambling code
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Data rate allocation decisions are made for a communications channel, such as a wireless reverse link connection. A first parameter used in this determination is a path loss, which is determined by the following process. First, a message is sent from a first station to a second station, such as on a paging channel. The message indicates a forward Effective Radiated Power (ERP) of a pilot signal transmitted by the first station. The second station then determines the received signal strength of this pilot signal, taking into account receiver gains. The path loss can then be estimated by the second station as the difference between the forward ERP data value that it received and the detected received pilot power. The second station also then preferably determines a transmit power level when transmitting a message back to the first station. This transmit power level information is encoded as a digital data word together with the forward path loss information as calculated by the first station. Upon receipt of these two pieces of information by the first station, the forward path loss estimate as calculated by the second station, and the output power value of the second station, the first station can then determine the amount of excess power available at the field unit. This excess power difference is indicative of the amount of dynamic range available in the transmit power amplifier in the particular second station. With this information, the first station can then make a determination as to whether coding rates which require a higher dynamic range will be acceptable for use by the particular second station.

Claims

1. A method for determining data rate for a communications channel comprising the steps of:

sending a first message from a first station to a second station, the message indicating an Effective Radiated Power (ERP) data value of signals transmitted by the first station;

measuring a signal strength for signal received at the second station;

computing a path loss estimate at the second station as the difference between the ERP data value that it received and the measured signal strength;

measuring the transmit power level for signals transmitted by the second station;

receiving a transmit power level information message sent from the second station and a forward path loss information message sent from the second station at the first station, and calculating an amount of excess power available at the second station; and

determining an acceptable data coding rate for transmission between the first station and the second station from the excess power available.

2. The method of claim 1, wherein determining an acceptable data coding rate includes selecting from among multiple available Forward Error Correction (FEC) coding rates.

3. The method of claim 1, wherein determining an acceptable data coding rate includes selecting from among available modulation rates.

4. The method of claim 1, wherein the first station is a base station and the second station is a field unit.

5. The method of claim 4, wherein the first message is sent on a paging channel.