Weighted open loop power control transmitter

• US 7,961,773 B2
• Filed: 05/12/2009
• Issued: 06/14/2011
• Est. Priority Date: 03/21/2000
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Shin, Sung-Hyuk, Zeira, Ariela
• Primary Examiner(s): Ghebretinsae; Temesghen
• Application Number:
  US12/464,164
• Publication Number:
  US 20090221239A1
• Time in Patent Office: 763 Days
• Field of Search: 375/130, 375/146, 375/295, 370/347, 370/318, 370/342, 370/343, 455/69, 455/522
• US Class Current: 375/130
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/246 where the output power of a terminal is based on a path parameter calculated in said terminal
• CPC Class Codes: H04W 52/248 where transmission power control commands are generated based on a path parameter

Abstract

A weighted open loop power control transmitter for controlling transmission power levels using a spread spectrum time division duplex (TDD) technique having frames with timeslots for communication includes a demodulator configured to receive a transmitted signal from the receiver, a channel estimation device, a data estimation device, and a weighted open loop power controller. The weighted open loop power controller includes a power measurement device, a pathloss estimation device configured to receive an interpreted power level from the data estimation device and estimate the pathloss and update a long term average of the pathloss, a quality measurement device, and a transmit power calculation device for determining the transmitter'"'"'s power level and to control the receiver'"'"'s amplifier.

Claims

1. A User Equipment (UE) comprising:

a receiver configured to receive a signal that includes a transmission power level parameter, over a channel;

a power measurement device configured to measure a power level of the received signal;

an average pathloss estimation device configured to;

determine an instantaneous pathloss, L, that is a difference in value of the transmission power level parameter and the measured power level of the received signal;

output an average pathloss, L_o, based upon the determined L;

a quality control device configured to;

determine a quality of the L_o;

apply a weighting factor α

having a value between 0 and 1; and

output a transmit power level adjustment; and

a transmit power level determination device configured to determine a power level of a subsequent transmission signal from the UE based on the transmit power level adjustment, wherein the power level of the subsequent transmission is directly proportional to a sum of three factors;

a first factor that is determined by multiplying the weighting factor α

with the difference of L and L_o;

a second factor that is L; and

a third factor that is at least one other value received by the UE.

2. The UE of claim 1, wherein the channel is a control channel.

3. The UE of claim 1, wherein the subsequent transmission signal from the UE takes place over at least one time slot of a radio frame that is divided into a plurality of time slots.

4. The UE of claim 1 comprising an antenna configured to radiate the subsequent transmission signal.

5. The UE of claim 1 further comprising circuitry operatively coupled to the antenna to demodulate signals received by the antenna to produce a baseband signal.

6. The UE of claim 1 wherein the received signal and the subsequently transmitted signal are in a code division multiple access format.

7. The UE of claim 1, wherein the weighting factor α

is directly proportional to;

a ratio of A/B wherein A is equal to a first slot number on which information is transmitted and B is equal to the maximum allowed delay as represented in slot numbers.

8. The UE of claim 1, wherein the weighting factor α

is directly proportional to a ratio of a parameter (D) that is calculated as a difference between a time slot of a previous path loss estimate and a first time slot of data transmitted, and a maximum allowed delay (D_max) as represented in time slots.

9. The UE of claim 8, wherein for D<

D_max, and D→

D_max, a difference between D and D_max is small, and the average pathloss estimation device is configured to determine the pathloss as an instantaneous pathloss L.

10. The UE of claim 8, wherein for D<

D_max, and a difference between D and D_max is large, and the average pathloss estimation device is configured to determine the pathloss as a long term average pathloss L_o.

11. The UE of claim 8, wherein for D>

D_max, the weighting factor is set to zero (0), and the average pathloss estimation device is configured to determine the pathloss as a long term average pathloss L_o.

12. The UE of claim 1, wherein the received signal is separated by time.

13. The UE of claim 1, wherein the received signal is separated by codes.

14. The UE of claim 1, wherein the received signal is separated by time and codes.