Granted Patent B2

US 9,584,354 · App. 14/899,516 · Granted Feb 28, 2017

Abstract

Claims (46)

1. A radio signal decoder comprising:

a receiver configured to receive a digitized radio signal, the radio signal having modulated subcarrier frequencies encoding digital information, wherein the modulated subcarrier frequencies include a first set of subcarrier frequencies with a first subcarrier spacing and a second set of subcarrier frequencies with a second subcarrier spacing, the second subcarrier spacing different from the first subcarrier spacing;

a first transformer configured with the first subcarrier spacing and configured to transform the digitized radio signal from a time domain into a frequency domain, the first transformer producing a first transformed signal having a value for each frequency in the first set of subcarrier frequencies;

a first decoder configured to reconstruct digital information from output of the first transformer;

an inverse transformer configured to:

receive as input at least a part of the output of the first transformer representing a frequency range overlapping the second set of subcarrier frequencies, and

transform the input from the frequency domain back to the time domain;

a second transformer configured with the second subcarrier spacing and configured to transform the output of the inverse transformer from the time domain to a frequency domain, the second transformer producing a second transformed signal having a value for each frequency in the second set;

a second decoder reconstructing digital information from output of the second transformer.

2. The radio signal decoder as in claim 1 , wherein the first subcarrier spacing is larger than the second subcarrier spacing.

3. The radio signal decoder as in claim 1 , wherein modulated subcarrier frequencies encode digital information in symbols, symbols modulated on a subcarrier frequency of the first set of subcarrier frequencies having a first symbol duration, symbols modulated on a subcarrier frequency of the second set of subcarrier frequencies having a second symbol duration, wherein the first symbol duration is smaller than the second symbol duration.

4. The radio signal decoder as in claim 3 , the first transformer operating on parts of the digitized radio signal having the first symbol duration in the time domain, the second transformer operating on parts of the digitized radio signal having the second symbol duration in the time domain, the radio signal decoder comprising a buffer so that the output of inverse transformer on which the second transformer operates has the second symbol duration in the time domain.

5. The radio signal decoder as in claim 4 , wherein the buffer is configured to receive from the first transformer and buffer the at least a part of output of the first transformer representing a frequency range overlapping the second set of subcarrier frequencies, the inverse transformer being configured to receive the input from the buffer.

6. The radio signal decoder as in claim 4 , wherein the buffer is configured to receive and buffer output from the inverse transformer obtained by transforming input of the inverse transformer from the frequency domain back to the time domain, the second transformer being configured to receive output of the inverse transformer from the buffer.

7. The radio signal decoder as in claim 1 , wherein the second decoder is configured for an inverse Fast Fourier Transform and peak search.

8. The radio signal decoder as in claim 1 , wherein the second decoder is configured for a correlation with a reference signature.

9. The radio signal decoder as in claim 1 , wherein the second decoder obtains an identifier of a user equipment.

10. The radio signal decoder as in claim 1 , wherein the first decoder is configured to first remove a cyclic prefix from the digitized radio signal, before transforming the digitized radio signal.

11. The radio signal decoder as in claim 1 , for decoding an LTE radio signal, wherein

the first set of subcarrier frequencies encodes at least PUSCH data, and

the second set of subcarrier frequencies encodes RACH data.

12. The radio signal decoder as in claim 1 , for decoding an LTE radio signal, wherein the first set of subcarrier frequencies encodes PUSCH, PUCCH and SRS data.

13. The radio signal decoder as in claim 11 , wherein at least one band allocated to PUSCH, PUCCH, and SRS is removed from the original signal before RACH signal processing by the second decoder.

14. The radio signal decoder as in claim 1 wherein the radio signal decoder is geographically distributed, the radio signal decoder having an antenna module and a decoding module, the antenna module comprising the receiver and first transformer, the decoding module comprising the first decoder, the inverse transformer, the second transformer and the second decoder, wherein the antenna module is configured to transmit the first transformed signal to the decoding module.

15. A method for decoding a radio signal, the method comprising:

receiving a digitized radio signal, the radio signal having modulated subcarrier frequencies encoding digital information, wherein the modulated subcarrier frequencies include a first set of subcarrier frequencies with a first subcarrier spacing and a second set of subcarrier frequencies with a second subcarrier spacing, the second subcarrier spacing different from the first subcarrier spacing;

transforming the digitized radio signal from a time domain into a frequency domain at a first transformer to produce a first transformed signal having a value for each frequency in the first set of subcarrier frequencies;

reconstructing digital information from output of the first transformer;

inverse transforming, comprising

receiving as input at least a part of the output of the first transformer representing a frequency range overlapping the second set of subcarrier frequencies, and

transforming the input from the frequency domain back to the time domain;

transforming the output of inverse transformer from the time domain to a frequency domain at a second transformer to produce a second transformed signal having a value for each frequency in the second set; and

reconstructing digital information from output of the second transformer.

16. A radio signal decoder comprising:

a receiver configured to receive a digitized radio signal, the radio signal having modulated subcarrier frequencies encoding digital information, wherein the modulated subcarrier frequencies include a first set of subcarrier frequencies and a second set of subcarrier frequencies, and wherein modulated subcarrier frequencies encode digital information in symbols, the symbols modulated on a first subcarrier frequency of the first set of subcarrier frequencies having a first symbol duration, the symbols modulated on a second subcarrier frequency of the second set of subcarrier frequencies having a second symbol duration, wherein the first symbol duration is different than the second symbol duration;

a first transformer configured to transform the digitized radio signal from a time domain into a frequency domain, the first transformer producing a first transformed signal having a value for each frequency in the first set of subcarrier frequencies;

a first decoder configured to reconstruct digital information from output of the first transformer;

an inverse transformer configured to:

receive as input at least a part of the output of the first transformer representing a frequency range overlapping the second set of subcarrier frequencies, and

transform the input from the frequency domain back to the time domain;

a second transformer configured to transform output of the inverse transformer from the time domain to a frequency domain, the second transformer producing a second transformed signal having a value for each frequency in the second set;

a second decoder reconstructing digital information from the output of the second transformer.

17. The radio signal decoder as in claim 16 , the first transformer operating on parts of the digitized radio signal having the first symbol duration in the time domain, the second transformer operating on parts of the digitized radio signal having the second symbol duration in the time domain, the radio signal decoder comprising a buffer so that output of inverse transformer on which the second transformer operates has the second symbol duration in the time domain.

18. The radio signal decoder as in claim 17 , wherein the buffer is configured to receive from the first transformer and buffer the at least a part of output of the first transformer representing a frequency range overlapping the second set of subcarrier frequencies, the inverse transformer being configured to receive the input from the buffer.

19. The radio signal decoder as in claim 17 , wherein the buffer is configured to receive and buffer output from the inverse transformer obtained by transforming the input of the inverse transformer from the frequency domain back to the time domain, the second transformer being configured to receive output of the inverse transformer from the buffer.

20. The radio signal decoder as in claim 16 , wherein the first symbol duration is smaller than the second symbol duration.

Assignments (9)