Method and apparatus for adaptive bit resolution in a digital receiver and digital transmitter

• US 6,504,863 B1
• Filed: 09/07/1999
• Issued: 01/07/2003
• Est. Priority Date: 09/07/1999
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Hellmark, L. Martin
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): TRAN, KHANH C
• Application Number:
  US09/391,336
• Time in Patent Office: 1,218 Days
• Field of Search: 375/219, 375/245, 375/345, 375/346, 375/350, 341/51, 341/132, 341/139, 341/145, 341/144, 341/155, 341/156, 341/169, 341/152, 341/200, 455/574, 455/575, 455/134, 455/135, 455/136, 455/138, 455/226.2, 455/226.3, 455/226.4
• US Class Current: 375/219
• CPC Class Codes: H03M 1/129 Means for adapting the input signal to the range the converter can handle, e.g. limiting, pre-scaling H03M1/18 takes precedence; Out-of-range indication
• CPC Class Codes: H03M 1/185 the determination of the range being based on more than one digital output value, e.g. on a running average, a power estimation or the rate of change
• CPC Class Codes: H03M 1/66 Digital/analogue converters H03M1/001 – H03M1/10 take precedence

Abstract

A transceiver includes a receiver and a transmitter. The receiver includes an analog-to-digital conversion device for converting a received analog signal to digital form, and the transmitter includes a digital-to-analog conversion device for converting a digital signal into analog form for transmission. A selector selects the resolutions of the conversion devices. The resolution of the analog-to-digital conversion device is selected based on a received signal quality, e.g., the signal-to-noise ratio or the signal-to interference ratio. The resolution of the digital-to-analog conversion device is selected based on a crest factor of the transmitted signal, the crest factor depending, e.g., on the modulation format of the signal being transmitted. The higher the crest factor, the higher the resolution selected.

Claims

1. A receiver comprising:

an analog-to-digital conversion device for converting a received analog signal into a digital signal; and

a selector for selecting a resolution of the conversion device, wherein the resolution of the conversion device is selected based on a signal quality of the received signal.

2. The receiver of claim 1, wherein the resolution is selected based on the signal to noise ratio or signal to interference ratio of the received signal.

3. The receiver of claim 1, wherein the resolution of the conversion device is selected depending on how much better the signal quality is than what is needed.

4. A transmitter comprising:

a digital-to-analog conversion device for converting a digital signal to analog form for transmission; and

a selector for selecting a resolution of the conversion device, wherein the resolution of the conversion device is selected based on a crest factor of the signal for transmission.

5. The transmitter of claim 4, wherein the crest factor depends on a modulation format of the signal for transmission.

6. The transmitter of claim 4, wherein the higher the crest factor, the higher the resolution selected.

7. A transceiver comprising:

an analog-to-digital conversion device for converting a received analog signal into a digital signal;

a digital-to-analog conversion device for converting a digital signal to analog form for transmission; and

a selector for selecting resolutions of the conversion devices, wherein the resolution of the analog-to-digital conversion device is selected based on a signal quality of the received signal, and the resolution of the digital-to-analog conversion device is selected based on a crest factor of the signal for transmission.

8. The transceiver of claim 7, wherein the resolution of the analog-to-digital conversion device is selected based on the signal to noise ratio or signal to interference ratio of the received signal, and the crest factor is selected depending on the modulation format.

9. The transceiver of claim 7, wherein the resolution of the analog-to-digital, conversion device is selected depending on how much better the signal quality than what is needed, and the higher the crest factor, the higher the selected resolution of the digital-to-analog converter.

10. A method of adapting bit resolution in a receiver, comprising the steps of:

selecting a resolution of an analog-to-digital conversion device based on a signal quality of a received analog signal; and

converting the received analog signal into a digital signal in the analog-to-digitat conversion device,

wherein the resolution is selected based on the signal to noise ratio or signal to interference ratio of the received signal.

11. A method of adapting bit resolution in a receiver, comprising the steps of:

selecting a resolution of an analog-to-digital conversion device based on a signal quality of a received analog signal; and

converting the received analog signal into a digital signal in the analog-to-digital conversion device,

wherein the resolution is selected depending on how much better the received signal quality is than what is needed.

12. A method of adapting bit resolution in a digital transmitter, comprising the steps of:

selecting a resolution of a digital-to-analog conversion device based on a crest factor of a digital signal for transmission; and

converting the digital signal into an analog signal for transmission in the digital-to-analog conversion device.

13. The method of claim 12, wherein the crest factor depends on a modulation format of the signal for transmission.

14. The method of claim 12, wherein the higher the crest factor, the higher the resolution selected.

15. A method of adapting bit resolution in a digital transceiver, comprising the steps of:

selecting a resolution of an analog-to-digital conversion device based on a signal quality of a received analog signal;

converting the received analog signal into a digital signal in the analog-to-digital conversion device;

selecting a resolution of a digital-to-analog conversion device based on a crest factor of a digital signal for transmission; and

converting the digital signal into an analog signal for transmission in the digital-to-analog conversion device.

16. The method of claim 15, wherein the resolution of the analog-to-digital conversion device is selected based on the signal to noise ratio or signal to interference ratio of the received signal, and the crest factor depends on the modulation format.

17. The method of claim 15 wherein the resolution of the analog-to-digital conversion device is selected depending on how much better the received signal quality is than what is needed, and the higher the crest factor, the higher the selected resolution of the digital-to-analog conversion device.