Packet correlator for a radio transmission system

Patent metadata

Field	Value
Publication number	US-11611369-B2
Application number	US-202017069282-A
Country	US
Kind code	B2
Filing date	Oct 13, 2020
Priority date	Apr 20, 2018
Publication date	Mar 21, 2023
Grant date	Mar 21, 2023

Abstract

A data receiver is configured to receive a signal including a plurality of partial data packets, wherein the plurality of partial data packets each include part of a data packet, wherein the data receiver includes a multi-stage correlator that is configured to perform multi-stage correlation to detect the partial data packets in the received signal, wherein a second correlation stage of the multi-stage correlator operates based on correlation results of a first correlation stage of the multi-stage correlator.

First claim

The invention claimed is:

1. A data receiver configured to receive a signal comprising a plurality of partial data packets, wherein each of the plurality of partial data packets comprises part of a data packet, the data receiver comprising:
a multi-stage correlator configured to perform multi-stage correlation to detect the plurality of partial data packets in the received signal,
wherein a second correlation stage of the multi-stage correlator operates based on correlation results of a first correlation stage of the multi-stage correlator,
wherein the plurality of partial data packets are distributed in time and frequency according to a hopping pattern, and
wherein the multi-stage correlator is configured to detect the plurality of partial data packets in the received signal or in a signal derived from the received signal,
wherein at least two groups of partial data packets of the plurality of partial data packets comprise a same relative group hopping pattern in groups, and
wherein the second correlation stage is configured to select groups of correlation results based on a group correlation pattern derived from a group hopping pattern from a set of correlation results of the first correlation stage and to combine them in groups to acquire a set of correlation results of the second correlation stage.

2. The data receiver according to claim 1 ,
wherein the multi-stage correlator is configured to detect the plurality of partial data packets based on preambles of the plurality of partial data packets in the received signal.

3. The data receiver according to claim 2 ,
wherein the received signal comprises a plurality of subband signals, wherein the plurality of subband signals comprise different subbands of the received signal.

4. The data receiver according to claim 3 ,
wherein the plurality of subband signals are used directly for a correlation performed by the multi-stage correlator.

5. The data receiver according to claim 3 ,
wherein the multi-stage correlator is configured to perform multi-stage correlation of at least one subset of the plurality of subband signals to detect the plurality of partial data packets in the at least one subset of the plurality of subband signals.

6. The data receiver according to claim 3 ,
wherein the data receiver is configured to multiply the plurality of subband signals with at least one complex exponential oscillation to increase a frequency resolution in the multi- stage correlator.

7. The data receiver according to claim 6 ,
wherein the exponential oscillations are applied to reference symbols.

8. The data receiver according to claim 1 ,
wherein the first correlation stage of the multi-stage correlator is configured to correlate the received signal or the signal derived therefrom with a plurality of preamble portions that correspond to different portions of preambles of the plurality of partial data packets to acquire a plurality of portion correlation results, and
wherein the first correlation stage is configured to combine the plurality of portion correlation results to acquire a set of correlation results or a subset of correlation results as the correlation results of the first correlation stage.

9. The data receiver according to claim 8 ,
wherein the first correlation stage is configured to normalize the plurality of portion correlation results.

10. The data receiver according to claim 8 ,
wherein the first correlation stage is configured to normalize the plurality of portion correlation results in dependence on a determined power of the received signal or the signal derived therefrom.

11. The data receiver according to claim 10 ,
wherein the power for normalization is determined across several subbands.

12. The data receiver according to claim 10 ,
wherein the power for normalization is determined based on synchronization symbols and at least one data symbol of the respective partial data packets.

13. The data receiver according to claim 10 ,
wherein the first correlation stage is configured to normalize the portion correlation results separately, and
wherein the power is determined separately for each preamble portion or together for all preamble portions.

14. The data receiver according to claim 8 ,
wherein the first correlation stage comprises a plurality of queue caches that are configured to cache the respective portion correlation results,
wherein the plurality of queue caches comprise different memory lengths, and
wherein the memory lengths of the plurality of queue caches depend on the respective preamble portions of the preambles of the plurality of partial data packets.

15. The data receiver according to claim 3 ,
wherein the first correlation stage is configured to correlate at least two subband signals of the plurality of subband signals, each with a plurality of preamble portions, to acquire a subset of correlation results for each subband signal of the at least two subband signals, and
wherein the first correlation stage is configured to provide a set of correlation results comprising the subsets of correlation results as correlation results of the first correlation stage.

16. The data receiver according to claim 15 ,
wherein the set of correlation results of the first correlation stage is a two-dimensional array of correlation results,
wherein a first dimension of the two-dimensional array of correlation results describes sampling instants of the received signal, and
wherein a second dimension of the two-dimensional array of correlation results describes subbands of a signal to be received.

17. The data receiver according to claim 8 ,
wherein the first correlation stage comprises an output queue cache that is configured to cache the set of correlation results of the first correlation stage.

18. The data receiver according to claim 8 ,
wherein the first correlation stage is configured to calculate a maximum across correlation results of adjacent subband signals and to discard smaller values.

19. The data receiver according to claim 8 ,
wherein the plurality of partial data packets comprise at least two different preambles,
wherein the first correlation stage is configured to correlate the received signal with a second plurality of preamble portions corresponding to different portions of a second preamble of the plurality of partial data packets to acquire at least a second plurality of portion correlation results, and
wherein the first correlation stage is configured to combine the second plurality of portion correlation results to acquire a second set of correlation results or a second subset of correlation results.

20. The data receiver according to claim 19 ,
wherein the at least two different preambles comprise different lengths.

21. The data receiver according to claim 1 ,
wherein the plurality of partial data packets comprise a same preamble.

22. The data receiver according to claim 1 ,
wherein the second correlation stage is configured to select the groups of correlation results from the set of correlation results of the first correlation stage in temporal and/or frequency direction based on the group correlation pattern.

23. The data receiver according to claim 1 ,
wherein the set of correlation results of the first correlation stage is a two-dimensional array of correlation results, and
wherein the group correlation pattern indicates time intervals and frequency spacings of the correlation results of the two-dimensional

Assignees

• Fraunhofer Ges Forschung
• Fraunhofer Ges Zur F Rderung Der Angewandten Forschung E V

Inventors

• Gamm Eberhard
• Kilian Gerd
• Kneissl Jakob
• Bernhard Josef
• Siebenhaar Markus

Classifications

• H04J13/107

  by concatenation · CPC title

• H04B1/713 Primary

  using frequency hopping · CPC title

• H04B1/709 Primary

  Correlator structure · CPC title

• H04B1/7093

  Matched filter type · CPC title

• H04B1/7156 Primary

  Arrangements for sequence synchronisation · CPC title