Multi-band single-carrier modulation

• US 20050013386A1
• Filed: 06/22/2004
• Published: 01/20/2005
• Est. Priority Date: 07/18/2003
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Ojard, Eric J.
• Granted Patent: US 7,362,829 B2
• Time in Patent Office: Days
• US Class Current: 375/316
• CPC Class Codes: H04B 1/71637 Receiver aspects H04B1/7183 takes precedence
• CPC Class Codes: H04B 1/719 Interference-related aspects
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

Multi-band single-carrier modulation. A novel approach is presented by which interference compensation may be performed for signals received by a piconet operable device. The piconet operable device may be implemented within a region that includes two or more SOPs (Simultaneously Operating Piconets). Estimation of the level and location of interference is performed and the input to a decoder (within the piconet operable device) is selectively weighted to ensure that the effect of any existent interference within the signal received by the piconet operable device is minimized. Different interference levels are dealt with differently. For one example, portions of the received signal having undergone a large amount of interference may be simply treated as erasures with respect to the input the decoder. For another example, portions of the received signal having undergone some smaller degree of interference, but some interference nonetheless, may be de-weighted before being provided to the decoder.

Claims

1. A method for operating a piconet operable device, the method comprising:

receiving a signal that includes a symbol;

detecting an energy of the symbol;

comparing the energy of the symbol to a predetermined energy or to an estimated energy;

determining whether a difference between the energy of the symbol and the predetermined energy exceeds at least one threshold from among a plurality of thresholds or whether a difference between the energy of the symbol and the estimated energy exceeds at least one threshold from among a plurality of thresholds;

when the difference exceeds a first threshold of the plurality of thresholds and no other threshold of the plurality of thresholds, selectively de-weighting the symbol according to a first de-weighting factor and providing the de-weighted symbol to a decoder;

when the difference exceeds the first threshold and a second threshold of the plurality of thresholds and no other threshold of the plurality of thresholds, selectively de-weighting the symbol according to a second de-weighting factor and providing the de-weighted symbol to a decoder; and

when the difference does not exceed any threshold of the plurality of thresholds, providing the symbol to the decoder.

2. The method of claim 1, further comprising:

when the difference exceeds the each threshold of the plurality of thresholds, treating interference affected bits of the symbol as erasures.

3. The method of claim 1, wherein:

the piconet operable device is a first piconet operable device that operates within a first piconet that substantially occupies a first region;

a second piconet operable device operates within a second piconet that substantially occupies a second region; and

the first region and the second region occupy at least a portion of common space.

4. The method of claim 3, wherein:

the symbol is a first symbol that collides with a second symbol that is received by the second piconet operable device before being received.

5. The method of claim 3., wherein:

collisions between symbols within the first piconet and symbols within the second piconet occur according to a structured interference pattern.

6. The method of claim 5, wherein the structured interference pattern is a predetermined structured interference pattern;

and further comprising;

at least one threshold from among the plurality of thresholds based on the predetermined structured interference pattern.

7. The method of claim 1, further comprising:

estimating at least one of a location and a level of interference of the symbol using the detected energy of the symbol.

8. The method of claim 1, further comprising:

when the difference exceeds the first threshold of the plurality of thresholds and no other threshold of the plurality of thresholds, selectively de-weighting the symbol according to a first de-weighting factor and de-interleaving the de-weighted symbol before providing the de-weighted symbol to the decoder.

9. The method of claim 1, further comprising:

when the difference exceeds the first threshold and the second threshold of the plurality of thresholds and no other threshold of the plurality of thresholds, selectively de-weighting the symbol according to the second de-weighting factor and de-interleaving the de-weighted symbol before providing the de-weighted symbol to the decoder.

10. The method of claim 1, further comprising:

when the difference does not exceed any threshold of the plurality of thresholds, de-interleaving the symbol before providing the symbol to the decoder.

12. The device of claim 1, wherein:

the demodulator estimates interference associated with the collision within the symbol on a power per bit basis.

11. A piconet operable device, the device comprising:

a radio front end that receives and filters a continuous time signal;

an ADC (Analog to Digital Converter) that samples the received and filtered continuous time signal thereby generating a discrete time signal and extracting I, Q (In-phase, Quadrature) components there from;

a demodulator that receives the I, Q components and performs symbol mapping of the I, Q components thereby generating a sequence of discrete-valued modulation symbols;

wherein the demodulator estimates at least one of a location and a level of interference associated with a collision within a symbol of the sequence of discrete-valued modulation symbols;

wherein the demodulator categories the level of the interference into at least two categorizes;

when the level of the interference is categorized into a first category of the at least two categorizes, the demodulator treats interference affected bits of the symbol as erasures thereby generating a first demodulator output symbol;

when the level of the interference is categorized into a second category of the at least two categorizes, the demodulator selectively de-weights interference affected bits of the symbol according to a de-weighting factor thereby generating a second demodulator output symbol; and

a decoder that decodes the first demodulator output symbol or the second demodulator output symbol to make best estimates of the at least one information bit contained therein.

13. The device of claim 11, wherein:

the location of interference associated with the collision within the symbol is used to identify the interference affected bits of the symbol.

14. The device of claim 11, wherein:

demodulator is implemented as a baseband processor/MAC (Medium Access Controller) within the piconet operable device.

15. The device of claim 11, wherein:

the piconet operable device is a first piconet operable device that operates within a first piconet that substantially occupies a first region;

a second piconet operable device operates within a second piconet that substantially occupies a second region; and

the first region and the second region occupy at least a portion of common space.

16. The device of claim 15, wherein:

the symbol is a first symbol that collides with a second symbol that is received by the second piconet operable device before being received.

17. The device of claim 15, wherein:

collisions between symbols within the first piconet and symbols within the second piconet occur according to a structured interference pattern.

18. The device of claim 17, wherein:

the structured interference pattern is a predetermined structured interference pattern; and

the demodulator estimates at least one of the location and the level of interference associated with the collision within the symbol based on the predetermined structured interference pattern.

19. The device of claim 11, wherein:

the demodulator estimates the level of interference associated with the collision within the symbol by measuring a total instantaneous power of the continuous time signal associated with the symbol, averaging a power of the continuous time signal associated with the symbol, and subtracting an expected reference signal power associated with the symbol from a previously obtained channel estimate or power measurement of the continuous time signal associated with the symbol.

20. The device of claim 11, wherein:

when the level of the interference is categorized into a third category of the at least two categorizes, the decoder directly decodes the symbol to make best estimates of the at least one information bit contained therein.

21. A piconet operable device, the device comprising:

a radio front end that receives and filters a first continuous time signal that has been transmitted using a single carrier frequency;

a frequency hopping mixer that mixes the first continuous time signal thereby generating a second continuous time signal;

a LPF (Low Pass Filter) that filters the second continuous time signal;

an ADC (Analog to Digital Converter) that samples the filtered, second continuous time signal thereby generating a discrete time signal and extracting I, Q (In-phase, Quadrature) components there from;

a demodulator that receives the I, Q components and performs symbol mapping of the I, Q components thereby generating a sequence of discrete-valued modulation symbols;

wherein the demodulator determines an average total signal power of a symbol of the sequence of discrete-valued modulation symbols;

wherein the demodulator subtracts a reference signal power estimate from the average total signal power of the symbol to generate a de-weighting factor;

the demodulator selectively de-weights interference affected bits of the symbol according to the de-weighting factor thereby generating a demodulator output symbol; and

a decoder that decodes the demodulator output symbol to make best estimates of the at least one information bit contained therein.

22. The device of claim 21, wherein:

the demodulator estimates at least one of a location and a level of interference associated with a collision within the symbol of the sequence of discrete-valued modulation symbols;

the demodulator categories the level of the interference into at least two categorizes;

when the level of the interference is categorized into a first category of the at least two categorizes, the demodulator treats interference affected bits of the symbol as erasures thereby generating a first demodulator output symbol; and

when the level of the interference is categorized into a second category of the at least two categorizes.

23. The device of claim 22, wherein:

when the level of the interference is categorized into a third category of the at least two categorizes, the decoder directly decodes the symbol to make best estimates of the at least one information bit contained therein.

24. The device of claim 22, wherein:

the demodulator estimates interference associated with the collision within the symbol on a power per bit basis.

25. The device of claim 22, wherein:

the location of interference associated with the collision within the symbol is used to identify the interference affected bits of the symbol.

26. The device of claim 21, wherein:

the piconet operable device is a first piconet operable device that operates within a first piconet that substantially occupies a first region;

a second piconet operable device operates within a second piconet that substantially occupies a second region; and

the first region and the second region occupy at least a portion of common space.

27. The device of claim 26, wherein:

the symbol is a first symbol that collides with a second symbol that is received by the second piconet operable device before being received.

28. The device of claim 26, wherein:

collisions between symbols within the first piconet and symbols within the second piconet occur according to a structured interference pattern.

29. The device of claim 28, wherein:

the structured interference pattern is a predetermined structured interference pattern; and

the demodulator estimates at least one of a location and a level of interference associated with a collision within the symbol of the sequence of discrete-valued modulation symbols based on the predetermined structured interference pattern.

30. The device of claim 21, further comprising:

an interleaver that interleaves the demodulator output symbol before the decoder decodes the demodulator output symbol to make best estimates of the at least one information bit contained therein.