Multiple modulation wireless transmitter

• US 6,906,996 B2
• Filed: 05/20/2002
• Issued: 06/14/2005
• Est. Priority Date: 05/20/2002
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ballantyne, Gary John
• Primary Examiner(s): Nguyen, Simon
• Application Number:
  US10/152,200
• Publication Number:
  US 20030216126A1
• Time in Patent Office: 1,121 Days
• Field of Search: 455/91, 455/102, 455/127.4, 455/522, 455/552.1, 375/135, 375/146, 375/261, 375/295, 375/298, 370/204
• US Class Current: 370/204
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A dual modulation transmitter apparatus (100) includes first (134), second (136), and third (132) signal paths. The first signal path includes a polar modulator (120) coupled to a data input (115). The second signal path includes a quadrature modulator (122) coupled to the data input. The third signal path is coupled to an antenna (142) and includes a switch (128) configured to couple the third signal path to the first signal path under a first condition and to couple the third signal path to the second signal path under a second condition. Thus, the transmitter apparatus enjoys the best of both worlds, since it utilizes quadrature or polar modulation in the most appropriate circumstances.

Claims

1. A dual modulation transmitter apparatus, comprising:

a first signal path including a polar carrier modulator coupled to a data input;

a second signal path including a quadrature carrier modulator coupled to the data input;

a third signal path coupled to an antenna and including a switch configured to couple the third signal path to the first signal path under a first condition and alternatively to couple the third signal path to the second signal path under a second condition.

2. The apparatus of claim 1, further comprising a controller coupled to the switch, where the controller is configured to set the switch to couple the third signal path to the first signal path under the first condition and to set the switch to couple the third signal path to the second signal path under the second condition.

3. The apparatus of claim 1, where the switch is configured such that the first condition comprises transmit power level satisfying predetermined criteria, and the second condition comprises transmit power level not satisfying the predetermined criteria.

4. The apparatus of claim 3, where transmit power comprises one of the following:

measured transmit power of the antenna;

a level of transmit power selected by a transmit power selector module for use in transmitting signals via the antenna.

5. The apparatus of claim 3, the predetermined criteria comprising transmit power exceeding a prescribed threshold.

6. The apparatus of claim 3, the predetermined criteria comprising transmit power exceeding a prescribed first threshold, the predetermined criteria additionally being satisfied by the transmit power decreasing from levels greater than the first threshold to levels less than the first threshold but still exceeding a prescribed second threshold.

7. The apparatus of claim 1, where the switch is configured such that the first condition comprises the antenna receiving designated signals having signal strength satisfying a predetermined criteria, and the second condition comprises the designated signals having signal strength that does not satisfy the predetermined criteria.

8. The apparatus of claim 7, the predetermined criteria comprising signal strength being less than a first prescribed threshold, the predetermined criteria additionally being satisfied by the signal strength increasing from levels less than the first threshold to levels greater than the first threshold but still not exceeding a prescribed second threshold.

9. The apparatus of claim 1, where the data input comprises output of a fourth signal path including a digital signal encoder, and the switch is configured such that the first and second conditions comprise different encoding schemes being used by the encoder.

10. The apparatus of claim 1, where:

the data input comprises output of a fourth signal path including a digital signal encoder;

the switch is configured such that the first condition comprises any one of the following (a) the encoder using a frequency modulation (FM) scheme, or (b) the encoder utilizing a code division multiple access (CDMA) encoding scheme and transmit power level satisfying a predetermined criteria;

the switch is configured such that the second condition comprises the encoder utilizing the CDMA encoding scheme and transmit power level not satisfying the predetermined criteria.

11. A dual modulation transmitter apparatus configured to transmit at various power levels responsive to various conditions, comprising:

a first signal path including a polar carrier modulator coupled to a data input;

a second signal path including a quadrature carrier modulator coupled to the data input;

a third signal path coupled to an antenna and including a switch configured to couple the third signal path to the first signal path responsive to conditions for which the transmitter apparatus is configured to transmit at power levels that satisfy predetermined criteria and to couple the third signal path to the second signal path responsive to conditions for which the transmitter apparatus is configured to transmit at power levels that do not satisfy the predetermined criteria.

12. A dual modulation transmitter apparatus, comprising:

a first signal path including means for polar carrier modulation of signals arriving at a data input;

a second signal path including means for quadrature carrier modulation of signals arriving at the data input;

a third signal path coupled to an antenna and including switching means for coupling the third signal path to the first signal path under a first condition and alternatively coupling the third signal path to the second signal path under a second condition.

13. A method for operating a transmitter to perform dual mode modulation of a carrier with a data signal, comprising operations of:

if a first condition exists, modulating the carrier with a data signal by applying polar modulation;

alternatively, in the absence of the first condition, modulating the carrier with a data signal by applying quadrature modulation.

14. The method of claim 13, where the first condition comprises transmit power level satisfying predetermined criteria, and the second condition comprises transmit power level not satisfying the predetermined criteria.

15. The method of claim 14, where transmit power comprises one of the following:

measured transmit power of the antenna;

a level of transmit power selected by a transmit power selector module for use in transmitting signals via the antenna.

16. The method of claim 13, the predetermined criteria comprising transmit power exceeding a prescribed threshold.

17. The method of claim 13, the predetermined criteria comprising transmit power exceeding a prescribed first threshold, the predetermined criteria additionally being satisfied by transmit power decreasing from levels greater than the first threshold to levels less than the first threshold but still exceeding a prescribed second threshold.

18. The method of claim 13, where the transmitter and a receiver are exchanging signals with a remote station, and the first condition comprises the receiver receiving designated signals having signal strength satisfying predetermined criteria, and the second condition comprises the designated signals having signal strength that does not satisfy the predetermined criteria.

19. The apparatus of claim 18, the predetermined criteria comprising signal strength being less than a prescribed first threshold, the first criteria additionally being satisfied by the signal strength increasing from levels less than the first threshold to levels that are greater than the first threshold but still do not exceed a prescribed second threshold.

20. The method of claim 13, where the first condition comprises the data signal having a first encoding type and the second condition comprises the data signal having a second encoding type.

21. The method of claim 13, where:

the first condition comprises any one of the following (a) the data signal being encoded with a frequency modulation (FM) scheme, or (b) the data signal being encoded with a code division multiple access (CDMA) encoding scheme and transmit power level satisfying a predetermined criteria;

the second condition comprises the encoder utilizing the CDMA encoding scheme and transmit power level not satisfying the predetermined criteria.