Pilot signal transmission for an orthogonal frequency division wireless communication system

• US 9,143,305 B2
• Filed: 03/17/2005
• Issued: 09/22/2015
• Est. Priority Date: 03/17/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gorokhov, Alexei, Naguib, Ayman Fawzy, Sutivong, Arak, Gore, Dhananjay Ashok, Ji, Tingfang
• Primary Examiner(s): MANOHARAN, MUTHUSWAMY GANAPATHY
• Application Number:
  US11/083,693
• Publication Number:
  US 20060209670A1
• Time in Patent Office: 3,841 Days
• Field of Search: 370/208, 370/491, 370/329, 370/260, 370/334, 370/203
• US Class Current: 1/1
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0039 Frequency-contiguous, i.e. with no allocation of frequencies for one user or terminal between the frequencies allocated to another
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04L 5/0062 Avoidance of ingress interference, e.g. ham radio channels
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601

Abstract

Transmission patterns for pilot symbols transmitted from a mobile station or base station are provided. The pattern allows for improved receipt of the pilot symbols transmitted. In addition, schemes for improving the ability to multiplex pilot symbols without interference and/or biasing from different mobile stations over the same frequencies and in the same time slots.

Claims

1. A wireless communication apparatus, comprising:

at least one antenna;

a memory that stores a plurality of pilot patterns, wherein the plurality of pilot patterns comprise;

at least one frequency selective pattern having mutually orthogonal clusters of contiguous pilot symbols to be transmitted from the wireless communication apparatus spanning multiple symbol periods and one frequency subcarrier, wherein, within the clusters of contiguous pilot symbols of the frequency selective pattern, only one pilot symbol is assigned to a first or last symbol period and none of the pilot symbols in the cluster are at a maximum or minimum frequency of a block of time and frequency resources designated for frequency hopping for estimation of a channel; and

at least one time selective pattern having mutually orthogonal clusters of contiguous pilot symbols to be transmitted from the wireless communication apparatus spanning multiple frequency subcarriers and one symbol period, wherein, within the clusters of contiguous pilot symbols of the time selective pattern, only one pilot symbol is assigned to the maximum or minimum frequency and none of the pilot symbols in the cluster are at the first or last symbol period of the block of time and frequency resources designated for frequency hopping for estimation of a channel, wherein

the memory stores a plurality of scalar functions for creating the pilot patterns; and

a processor coupled with the at least one antenna and the memory, the processor adapted to select one of the pilot patterns and multiply the pilot symbols of the selected pattern by the plurality of scalar functions prior to transmission of the pilot symbols from the antenna, wherein, within each of the selected pilot pattern, all of the pilot symbols share one of a common time interval and a common frequency interval.

2. The wireless communication apparatus of claim 1, wherein the memory stores another plurality of scalar functions and wherein the processor causes the pilot symbols to be multiplied by the plurality of scalar functions and the another plurality of scalar functions.

3. The wireless communication apparatus of claim 2, wherein the another plurality of scalar functions comprise vectors of scalar functions and wherein each vector is orthogonal to each other vector.

4. The wireless communication apparatus of claim 1, wherein the plurality of scalar functions comprise vectors of scalar functions and wherein each vector is orthogonal to each other vector.

5. The wireless communication apparatus of claim 1, wherein the processor varies a frequency range of the multiple frequency subcarriers between a first time period and a second time period so that no frequencies within the frequency range for the first time period are within the frequency range for the second time period.

6. The wireless communication apparatus of claim 1, wherein each of the plurality of scalar function multiplications consists of a phase shift to each sample of each symbol.

7. The wireless communication apparatus of claim 1, wherein the plurality of scalar functions comprise vectors of scalar functions and wherein each vector is quasi-orthogonal to each other vector.

8. The wireless communication apparatus of claim 7, wherein the processor multiplies the vectors of scalar functions and the pilot symbols utilizing a discrete Fourier transform.

9. A method for wireless communication comprising:

generating a plurality of pilot symbol patterns, wherein the plurality of pilot symbol patterns comprise;

at least one frequency selective pattern having mutually orthogonal clusters of contiguous pilot symbols to be transmitted from a wireless communication device spanning multiple symbol periods and one frequency subcarrier, wherein, within the clusters of contiguous pilot symbols of the frequency selective pattern, only one pilot symbol is assigned to a first or last symbol period and none of the pilot symbols in the cluster are at a maximum or minimum frequency of a block of time and frequency resources designated for frequency hopping for estimation of a channel; and

at least one time selective pattern having mutually orthogonal clusters of contiguous pilot symbols to be transmitted from the wireless communication device spanning multiple frequency subcarriers and one symbol period, wherein, within the clusters of contiguous pilot symbols of the time selective pattern, only one pilot symbol is assigned to the maximum or minimum frequency and none of the pilot symbols in the cluster are at the first or last symbol period of the block of time and frequency resources designated for frequency hopping for estimation of a channel, wherein the pilot symbol patterns are created by applying one of a plurality of scalar functions to each of the pilot symbols; and

selecting one of the pilot symbol patterns, wherein, within each cluster of the selected pilot symbol pattern, all of the pilot symbols share one of a common time interval and a common frequency interval.

10. The method of claim 9, wherein the plurality of scalar functions are grouped in vectors and wherein each vector is orthogonal to each other vector.

11. The method of claim 9, wherein said applying comprises shifting a phase of each sample that comprises each pilot symbol according to the scalar function.

12. The method of claim 9, further comprising applying another scalar function of another plurality of scalar functions to each of pilot symbols in the selected pilot symbol pattern.

13. The method of claim 12, wherein said applying another scalar function comprises varying over time the another scalar function applied to a pilot symbol of the selected pilot symbol pattern.

14. The method of claim 9, wherein the plurality of scalar functions comprise scalar functions unique to the wireless communication device.

15. The method of claim 9, wherein the plurality of scalar functions comprise scalar functions unique to a sector of a base station with which the wireless communication device communicates.

16. The method of claim 9, wherein the plurality of scalar functions comprise vectors of scalar functions and wherein each vector is quasi-orthogonal to each other vector.

17. The method of claim 9, wherein applying the plurality of scalar functions comprises utilizing a discrete Fourier transform in applying the scalar functions.

18. A method of wireless communication, comprising:

grouping a first plurality of pilot symbols into a plurality of mutually orthogonal clusters of contiguous pilot symbols arranged according to a first channel condition, wherein the plurality of mutually orthogonal clusters of contiguous pilot symbols comprise at least one frequency selective pilot symbol cluster and at least one time selective pilot symbol cluster, wherein, within the frequency selective pilot symbol cluster, only one pilot symbol is assigned to a first or last symbol period and none of the pilot symbols in the cluster are at a maximum or minimum frequency of a block of time and frequency resources designated for frequency hopping for estimation of a channel, and wherein, within the time selective pilot symbol cluster, only one pilot symbol is assigned to the maximum or minimum frequency and none of the pilot symbols in the cluster are at the first or last symbol period of the block of time and frequency resources designated for frequency hopping for estimation of a channel;

applying, at a first wireless communication device, a first plurality of scalar functions to the first plurality of pilot symbols to produce a processed first plurality of pilot symbols;

transmitting, from the first wireless communication device, the processed first plurality of pilot symbols during a plurality of time intervals and at a plurality of frequencies;

grouping a second plurality of pilot symbols into a plurality of mutually orthogonal clusters of contiguous pilot symbols arranged according to a second channel condition, wherein, within each cluster of one of said plurality of clusters, all of the pilot symbols share one of a common time interval and a common frequency interval;

applying, at a second wireless communication device, a second plurality of scalar functions different than the first plurality of scalar functions to the second plurality of pilot symbols to produce a processed second plurality of pilot symbols, wherein each cluster of the processed first plurality of pilot symbols is orthogonal to each other cluster of the processed first plurality of pilot symbols and to the processed second plurality of pilot symbols; and

transmitting, from the second wireless communication device, the processed second plurality of pilot symbols during the same plurality of time intervals and at the same plurality of frequencies as the processed first plurality of pilot symbols.

19. The method of claim 18, wherein the maximum frequency and the minimum frequency vary between a first time period and a second time period so that no frequencies between the minimum frequency and the maximum frequency for the first time period are between the minimum frequency and the maximum frequency for the second time period.

20. The method of claim 18, further comprising applying another scalar function of another plurality of scalar functions to each of the first plurality of pilot symbols.

21. The method of claim 20, wherein applying another scalar function comprises varying over time the another scalar function applied to each of the first plurality of pilot symbols.

22. The method of claim 21, further comprising selecting the first plurality of scalar functions based upon a sector of a base station to which the first wireless communication device is transmitting.

23. The method of claim 21, wherein the first plurality of scalar functions is unique to the first wireless communication device.

24. The method of claim 18, wherein the first plurality of scalar functions comprise vectors of scalar functions and wherein each vector is quasi-orthogonal to each other vector.

25. The method of claim 18, wherein said applying, at the first wireless communication device, a first plurality of scalar functions comprises utilizing a discrete Fourier transform in applying the first plurality of scalar functions.

26. A wireless communication apparatus comprising:

a plurality of antennas;

a memory that stores a plurality of pilot patterns each comprising a plurality of clusters of contiguous pilot symbols processed by a scalar function, wherein the plurality of pilot patterns comprise at least one time selective pilot pattern and at least one frequency selective pilot pattern, wherein;

the frequency selective pilot pattern comprises mutually orthogonal clusters of contiguous pilot symbols spanning multiple symbol periods and one frequency subcarrier, wherein, within the clusters of contiguous pilot symbols of the frequency selective pattern, only one pilot symbol is assigned to a first or last symbol period and none of the pilot symbols in the cluster are at a maximum or minimum frequency of a block of time and frequency resources designated for frequency hopping for estimation of a channel; and

the time selective pilot pattern comprises mutually orthogonal clusters of contiguous pilot symbols spanning multiple frequency subcarriers and one symbol period, wherein, within the clusters of contiguous pilot symbols of the time selective pattern, only one pilot symbol is assigned to the maximum or minimum frequency and none of the pilot symbols in the cluster are at the first or last symbol period of the block of time and frequency resources designated for frequency hopping for estimation of a channel; and

a processor coupled with the plurality of antennas and the memory, the processor adapted to select one pilot pattern of the plurality of pilot patterns to decode multiple pilot symbol groups received from a plurality of wireless devices at the plurality of antennas, wherein, within each cluster of the selected pattern, all of the pilot symbols share one of a common time interval and a common frequency interval.

27. The wireless communication apparatus of claim 26, wherein the memory further stores a plurality of sequences that are orthogonal to each other sequence of the plurality of sequences and wherein the processor selectively instructs multiplication of the pilot symbols of the selected pilot pattern with some of the sequences of the plurality of sequences prior to decoding the pilot symbols.

28. The wireless communication apparatus of claim 26, wherein the memory further stores another plurality of sequences and wherein the processor selectively instructs multiplication of the pilot symbols of the selected pilot pattern with both some of the plurality of sequences and some of the another plurality of sequences prior to decoding the pilot symbols.

29. The wireless communication apparatus of claim 28, wherein the processor generates an instruction, to be transmitted from at least one of the plurality of antennas, specifying a pilot pattern of the plurality of pilot patterns to be transmitted to the wireless communication apparatus.

30. A wireless communication apparatus, comprising:

a plurality of antennas;

a memory that stores a plurality of pilot patterns each of which comprises a plurality of clusters of contiguous pilot symbols, wherein a scalar function is applied to each of the clusters of contiguous pilot symbols to create the pilot patterns, and wherein the plurality of pilot patterns comprise at least one time selective pilot pattern and at least one frequency selective pilot pattern, wherein;

the frequency selective pilot pattern comprises mutually orthogonal clusters of contiguous pilot symbols spanning multiple symbol periods and one frequency subcarrier, wherein, within the clusters of contiguous pilot symbols of the frequency selective pattern, only one pilot symbol is assigned to a first or last symbol period and none of the pilot symbols in the cluster are at a maximum or minimum frequency of a block of time and frequency resources designated for frequency hopping for estimation of a channel; and

the time selective pilot pattern comprises mutually orthogonal clusters of contiguous pilot symbols spanning multiple frequency subcarriers and one symbol period, wherein, within the clusters of contiguous pilot symbols of the time selective pattern, only one pilot symbol is assigned to the maximum or minimum frequency and none of the pilot symbols in the cluster are at the first or last symbol period of the block of time and frequency resources designated for frequency hopping for estimation of a channel; and

a processor coupled with the plurality of antennas and the memory, the processor adapted to select one of the plurality of pilot patterns and cause a plurality of pilot symbols according to the selected pilot pattern to be transmitted from at least two of the plurality of antennas, wherein, within each cluster of the selected pilot pattern, all of the pilot symbols share one of a common time interval and a common frequency interval.

31. The wireless communication apparatus of claim 30, wherein the processor causes a plurality of pilot symbols according to another pilot pattern, different than the selected pilot pattern, to be transmitted from at least two of the plurality of antennas.

32. The wireless communication apparatus of claim 30, wherein the memory further stores a plurality of sequences that are orthogonal to each other sequence of the plurality of sequences and wherein the processor selectively instructs multiplication of the pilot symbols of the selected pilot pattern with some of the sequences of the plurality of sequences prior to transmitting the plurality of pilot symbols according to the selected pilot pattern.

33. The wireless communication apparatus of claim 30, wherein the memory further stores another plurality of sequences and wherein the processor selectively instructs multiplication of the pilot symbols of the selected pilot pattern with both some of the sequences of the plurality of sequences and some of the another plurality of sequences prior to transmitting the plurality of pilot symbols according to the selected pilot pattern.

34. The wireless communication apparatus of claim 33, wherein the processor generates an instruction, to be transmitted from at least one of the plurality of antennas, specifying a pilot pattern of the plurality of pilot patterns to be transmitted to the wireless communication apparatus.

35. A wireless communication apparatus comprising:

means for selecting a pilot pattern from a plurality of pilot patterns, wherein the plurality of pilot patterns comprise at least one frequency selective pilot pattern and at least one time selective pilot pattern, wherein;

the frequency selective pilot pattern comprises mutually orthogonal clusters of contiguous pilot symbols spanning multiple symbol periods and one frequency subcarrier, wherein, within the clusters of contiguous pilot symbols of the frequency selective pattern, only one pilot symbol is assigned to a first or last symbol period and none of the pilot symbols in the cluster are at a maximum or minimum frequency of a block of time and frequency resources designated for frequency hopping for estimation of a channel; and

the time selective pilot pattern comprises mutually orthogonal clusters of contiguous pilot symbols spanning multiple frequency subcarriers and one symbol period, wherein, within the clusters of contiguous pilot symbols of the time selective pattern, only one pilot symbol is assigned to the maximum or minimum frequency and none of the pilot symbols in the cluster are at the first or last symbol period of the block of time and frequency resources designated for frequency hopping for estimation of a channel, wherein, within each cluster of the selected pilot pattern, all of the pilot symbols share one of a common time interval and a common frequency interval;

means for arranging a plurality of contiguous pilot symbols according to the selected pilot pattern; and

means for applying a plurality of scalar functions to each of the plurality of pilot symbols prior to transmission of the pilot symbols.

36. The wireless communication apparatus of claim 35, wherein the means for applying comprises means for applying the plurality of scalar functions so that each cluster of contiguous pilot symbols is orthogonal to each other cluster of contiguous pilot symbols.

37. The wireless communication apparatus of claim 35, further comprising means for applying another scalar function of another plurality of scalar functions to each of the plurality of pilot symbols.

38. The wireless communication apparatus of claim 35, wherein applying another scalar function comprises varying over time the another scalar function applied to one of the pilot symbols.

39. The wireless communication apparatus of claim 35, wherein the plurality of scalar functions comprise scalar functions unique to the wireless communication device.

40. The wireless communication apparatus of claim 35, wherein the plurality of scalar functions comprise scalar functions unique to a sector of a base station with which the wireless communication device communicates.

41. A wireless communication apparatus comprising:

means for grouping a first plurality of pilot symbols into a plurality of mutually orthogonal clusters of contiguous pilot symbols according to a channel condition, wherein the plurality of mutually orthogonal clusters of contiguous pilot symbols comprise at least one frequency selective pilot symbol cluster and at least one time selective pilot symbol cluster, wherein, within the frequency selective pilot symbol cluster, only one pilot symbol is assigned to a first or last symbol period and none of the pilot symbols in the cluster are at a maximum or minimum frequency of a block of time and frequency resources designated for frequency hopping for estimation of a channel, and wherein, within the time selective pilot symbol cluster, only one pilot symbol is assigned to the maximum or minimum frequency and none of the pilot symbols in the cluster are at the first or last symbol period of the block of time and frequency resources designated for frequency hopping for estimation of a channel;

means for applying, at a first wireless communication device, a first plurality of scalar functions to the first plurality of pilot symbols to produce a processed first plurality of pilot symbols;

means for transmitting, from the first wireless communication device, the processed first plurality of pilot symbols during a plurality of time intervals and at a plurality of frequencies;

means for grouping a second plurality of pilot symbols into a plurality of clusters of contiguous pilot symbols, wherein, within each cluster of one of said plurality of clusters, all of the pilot symbols share one of a common time interval and a common frequency interval;

means for applying, at a second wireless communication device, a second plurality of scalar functions different than the first plurality of scalar functions to the second plurality of pilot symbols to produce a processed second plurality of pilot symbols, wherein each cluster of the processed first plurality of pilot symbols is orthogonal to each other cluster of the processed first plurality of pilot symbols and to the processed second plurality of symbols; and

means for transmitting, from the second wireless communication device, the processed second plurality of pilot symbols during the same plurality of time intervals and at the same plurality of frequencies as the processed first plurality of pilot symbols.

42. The wireless communication apparatus of claim 41, wherein the means for transmitting varies the maximum frequency and the minimum frequency between a first time period and a second time period so that no frequencies between the minimum frequency and the maximum frequency for the first time period are between the minimum frequency and the maximum frequency for the second time period.

43. The wireless communication apparatus of claim 41, further comprising means for applying another scalar function of another plurality of scalar functions to each of the first plurality of pilot symbols.

44. The wireless communication apparatus of claim 43, wherein the means for applying another scalar function comprises means for varying over time the another scalar function applied to each of the plurality of pilot symbols.

45. A machine-readable non-transitory medium encoded with instructions for performing wireless communication, the instructions comprising code for:

grouping a first plurality of pilot symbols into a plurality of clusters of contiguous pilot symbols according to a first channel condition, wherein the plurality of mutually orthogonal clusters of contiguous pilot symbols comprise at least one frequency selective pilot symbol cluster and at least one time selective pilot symbol cluster, wherein, within the frequency selective pilot symbol cluster, only one pilot symbol is assigned to a first or last symbol period and none of the pilot symbols in the cluster are at a maximum or minimum frequency of a block of time and frequency resources designated for frequency hopping for estimation of a channel, and wherein, within the time selective pilot symbol cluster, only one pilot symbol is assigned to the maximum or minimum frequency and none of the pilot symbols in the cluster are at the first or last symbol period of the block of time and frequency resources designated for frequency hopping for estimation of a channel;

Therein the plurality of clusters of pilot symbols are arranged close to the edges of a block of time and frequency resources designated for frequency hopping for estimation of a channel;

applying, at a first wireless communication device, a first plurality of scalar functions to the first plurality of pilot symbols to produce a processed first plurality of pilot symbols;

transmitting, from the first wireless communication device, the processed first plurality of pilot symbols during a plurality of time intervals and at a plurality of frequencies;

grouping a second plurality of pilot symbols into a plurality of clusters of contiguous pilot symbols according to a second channel condition, wherein, within each cluster of one of said plurality of clusters, all of the pilot symbols share one of a common time interval and a common frequency interval;

applying, at a second wireless communication device, a second plurality scalar functions different than the first plurality of scalar functions to the second plurality of pilot symbols to produce a processed second plurality of pilot symbols, wherein each cluster of the processed first plurality of pilot symbols is orthogonal to each other cluster of the processed first plurality of pilot symbols and to the processed second plurality of pilot symbols; and

transmitting, from the second wireless communication device, the processed second plurality of pilot symbols during the same plurality of time intervals and at the same plurality of frequencies as the processed first plurality of pilot symbols.