IP Library › Granted Patent US 7,706,758
Granted Patent B2
US 7,706,758 · App. 10/497,426 · Granted Apr 27, 2010

Controlling power supply between a voltage generator, a load and a rechargeable battery

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Quick Facts
Patent No.
US 7,706,758
App. No.
10/497,426
Granted
Apr 27, 2010
Kind
B2
Abstract

In an orthogonal frequency division multiplex communication system, for example a HIPERLAN/2 system, power amplifiers ( 224 ) of mobile terminals ( 4, 6 ) are switched off when not in use, and then switched on again when a signal transmission is to be made. This conserves power, but introduces a power amplifier transient ( 315 ). An access point ( 2 ), i.e. a type of base station, compensates for these power amplifier transients ( 315 ) using a simple scalar constant gain transient correction, over a full OFDM symbol (or a plurality of OFDM symbols). The correction is updated on an OFDM symbol by symbol basis (or plurality of symbols by plurality of symbols basis).

Claims (27)

1. A method of compensating a power amplifier transient of a received orthogonal frequency division multiplex, OFDM, signal, the method comprising:

measuring a power level of pilot symbols or carrier levels of the received OFDM signal to determine a scalar gain coefficient dependent upon the power amplifier transient; and

compensating the power amplifier transient using the scalar gain coefficient, wherein the scalar gain coefficient is determined as respective constant values for respective OFDM symbols or respective pluralities of OFDM symbols of the OFDM signal, and variable over different OFDM symbols or different pluralities of OFDM symbols of the OFDM signal.

2. A method according to claim 1 , wherein the step of compensating the power amplifier transient is performed on a plurality of symbols by plurality of symbols basis or on a symbol-by-symbol basis.

3. An orthogonal frequency division multiplex, OFDM, communication method, comprising:

transmitting an OFDM signal comprising a power amplifier transient;

receiving the OFDM signal comprising the power amplifier transient; and

compensating the power amplifier transient using a method according to claim 1 .

4. A method according to claim 3 , wherein the method is performed in a communication system in which an allowable degree of received signal degradation is specified, and, when the OFDM signal is received, the power amplifier transient would be accommodated to the specified allowable degree of signal degradation, if the compensation step were not performed.

5. A communication system adapted to perform the method of claim 3 .

6. A communication system according to claim 5 conforming to the HIPERLAN/2 system specification.

7. A method according to claim 1 , adapted for use in a HIPERLAN/2 communication system.

8. A storage medium storing processor-implementable instructions for controlling a processor to carry out the method of claim 1 .

9. A communication unit adapted to perform the method of claim 1 .

10. A communication unit according to claim 9 , in the form of an access point or a mobile terminal for a HIPERLAN/2 system.

11. A method of compensating a power amplifier transient of a received orthogonal frequency division multiplex, OFDM, signal, the method comprising:

measuring a power level of pilot symbols or carrier levels of the received OFDM signal to determine a scalar gain coefficient dependent upon the power amplifier transient; and

compensating the power amplifier transient using the scalar gain coefficient, wherein the scalar gain coefficient is determined by averaging over said pilot symbols or said carrier levels.

12. A method of compensating a power amplifier transient of a received orthogonal frequency division multiplex, OFDM, signal, the method comprising:

measuring a power level of pilot symbols or carriers of the received OFDM signal to determine a scalar gain coefficient dependent upon the power amplifier transient; and

compensating the power amplifier transient by equalizing the received OFDM signal using equalisation taps multiplied by the scalar gain coefficient.

13. A method of compensating a power amplifier transient of a received orthogonal frequency division multiplex, OFDM, signal, the method comprising:

measuring a power level of pilot symbols or carriers of the received OFDM signal to determine a scalar gain coefficient dependent upon the power amplifier transient; and

compensating the power amplifier transient by multiplying a channel estimate by an inverse of a determined scalar gain coefficient.

14. A method of compensating a power amplifier transient of a received orthogonal frequency division multiplex, OFDM, signal, the method comprising:

measuring a power level of pilot symbols or carriers of the received OFDM signal to determine a scalar gain coefficient dependent upon the power amplifier transient; and

compensating the power amplifier transient using a scalar gain coefficient to weight metrics used by a decoder.

Assignments (16)
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 11759915 AND REPLACE IT WITH APPLICATION 11759935 PREVIOUSLY RECORDED ON REEL 040925 FRAME 0001. ASSIGNOR(S) HEREBY CONFIRMS THE RELEASE OF SECURITY INTEREST. Recorded Feb 17, 2020
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: NXP, B.V. F/K/A FREESCALE SEMICONDUCTOR, INC.
Reel/Frame 052917/0001 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 11759915 AND REPLACE IT WITH APPLICATION 11759935 PREVIOUSLY RECORDED ON REEL 040928 FRAME 0001. ASSIGNOR(S) HEREBY CONFIRMS THE RELEASE OF SECURITY INTEREST. Recorded Jan 17, 2020
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: NXP B.V.
Reel/Frame 052915/0001 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION 11759915 AND REPLACE IT WITH APPLICATION 11759935 PREVIOUSLY RECORDED ON REEL 037486 FRAME 0517. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT AND ASSUMPTION OF SECURITY INTEREST IN PATENTS. Recorded Dec 10, 2019
From: CITIBANK, N.A.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 053547/0421 →
RELEASE OF SECURITY INTEREST Recorded Nov 7, 2016
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: NXP B.V.
Reel/Frame 040928/0001 →
RELEASE OF SECURITY INTEREST Recorded Sep 21, 2016
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: NXP, B.V., F/K/A FREESCALE SEMICONDUCTOR, INC.
Reel/Frame 040925/0001 →
ASSIGNMENT AND ASSUMPTION OF SECURITY INTEREST IN PATENTS Recorded Jan 12, 2016
From: CITIBANK, N.A.
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 037486/0517 →
PATENT RELEASE Recorded Dec 21, 2015
From: CITIBANK, N.A., AS COLLATERAL AGENT
To: FREESCALE SEMICONDUCTOR, INC.
Reel/Frame 037354/0225 →
PATENT RELEASE Recorded Dec 21, 2015
From: CITIBANK, N.A., AS COLLATERAL AGENT
To: FREESCALE SEMICONDUCTOR, INC.
Reel/Frame 037356/0143 →
PATENT RELEASE Recorded Dec 21, 2015
From: CITIBANK, N.A., AS COLLATERAL AGENT
To: FREESCALE SEMICONDUCTOR, INC.
Reel/Frame 037356/0553 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 7, 2015
From: ZENITH INVESTMENTS, LLC
To: APPLE INC.
Reel/Frame 034749/0791 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 3, 2014
From: FREESCALE SEMICONDUCTOR, INC.
To: ZENITH INVESTMENTS, LLC
Reel/Frame 033677/0920 →
SECURITY AGREEMENT Recorded Jun 18, 2013
From: FREESCALE SEMICONDUCTOR, INC.
To: CITIBANK, N.A., AS NOTES COLLATERAL AGENT
Reel/Frame 030633/0424 →
SECURITY AGREEMENT Recorded May 13, 2010
From: FREESCALE SEMICONDUCTOR, INC.
To: CITIBANK, N.A., AS COLLATERAL AGENT
Reel/Frame 024397/0001 →
SECURITY AGREEMENT Recorded Mar 15, 2010
From: FREESCALE SEMICONDUCTOR, INC.
To: CITIBANK, N.A.
Reel/Frame 024085/0001 →
SECURITY AGREEMENT Recorded Feb 2, 2007
From: FREESCALE SEMICONDUCTOR, INC.; FREESCALE ACQUISITION CORPORATION; FREESCALE ACQUISITION HOLDINGS CORP.; FREESCALE HOLDINGS (BERMUDA) III, LTD.
To: CITIBANK, N.A. AS COLLATERAL AGENT
Reel/Frame 018855/0129 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 16, 2004
From: BATEMAN, DAVID; SIMOENS, SEBASTIEN; DECOURVILLE, MARC
To: FREESCALE SEMICONDUCTOR, INC.
Reel/Frame 015470/0084 →