Pilot signal transmission for an orthogonal frequency division wireless communication system

• US 20060209732A1
• Filed: 10/27/2005
• Published: 09/21/2006
• Est. Priority Date: 03/17/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gore, Dhananjay Ashok, Naguib, Ayman Fawzy, Gorokhov, Alexei, Sutivong, Arak, Ji, Tingfang
• Granted Patent: US 9,461,859 B2
• Time in Patent Office: Days
• US Class Current: 370/310
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0216 with estimation of channel length
• CPC Class Codes: H04L 25/0222 Estimation of channel variability, e.g. coherence bandwidth, coherence time, fading frequency
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 25/03866 using scrambling
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04L 5/0058 Allocation criteria
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling

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 for frequency selective channels and users. 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 pattern of pilot symbols, each comprising a plurality of clusters; and

a processor coupled with the at least one antenna and the memory, the processor configured to select at least one pilot pattern of the plurality of pilot patterns for transmission by a user based upon a frequency selectivity threshold.

2. The wireless communication apparatus of claim 1, wherein the processor is further configured to select the at least one pilot pattern based upon whether the wireless communication device is to receive a transmission in a MIMO mode.

3. The wireless communication apparatus of claim 1, wherein the frequency selectivity threshold is a function of user mobility.

4. The wireless communication apparatus of claim 1, wherein the at least one pilot pattern comprises a frequency selective pilot pattern for mobile users.

5. The wireless communication apparatus of claim 1, wherein the memory comprises a plurality of scalar functions and wherein the processor is further configured to instruct multiplication of the pilots by at least one of the plurality of scalar functions.

6. The wireless communication apparatus of claim 5, wherein the plurality of scalar functions comprise vectors of scalar functions and wherein each vector is orthogonal to each other vector.

7. The wireless communication apparatus of claim 1, wherein the wireless communication apparatus receives signals using a plurality of frequency subcarriers in a frequency range between a maximum frequency and a minimum frequency and wherein the pilot symbol clusters each comprises a plurality of pilot symbols so that at least one the plurality of pilot symbols of each of the plurality of clusters is transmitted using a frequency subcarrier other than the maximum frequency or the minimum frequency.

8. The wireless communication apparatus of claim 1, wherein the frequency range comprises a frequency range of a time frequency block.

9. The wireless communication apparatus of claim 1, wherein the processor is further configured to select the at least one pilot pattern based upon the relationship of a delay spread of the user and the frequency selectivity threshold.

10. A wireless communication apparatus, comprising:

a memory that stores a plurality of patterns of pilot symbols, each comprising a plurality of clusters, to be transmitted from the wireless communication device; and

means, coupled with the memory, for selecting at least one pilot pattern of the plurality of pilot patterns for transmission by a user based upon a frequency selectivity threshold.

11. The wireless communication apparatus of claim 10, wherein the means further comprises means for selecting the at least one pilot pattern based upon whether the wireless communication device is to receive a transmission in a MIMO mode.

12. The wireless communication apparatus of claim 10, wherein the means further comprises means for selecting the at least one pilot pattern based upon a velocity of the user.

13. The wireless communication apparatus of claim 10, wherein the wireless communication apparatus receives signals using a plurality of frequency subcarriers in a frequency range between a maximum frequency and a minimum frequency and wherein the clusters each comprises a plurality of pilot symbols so that at least one the plurality of pilot symbols of each of the plurality of clusters is transmitted using a frequency subcarrier other than the maximum frequency or the minimum frequency.

14. The wireless communication apparatus of claim 13, wherein the means for selecting comprises means for selecting based upon relationship of a delay spread of the user and the frequency selectivity threshold.

15. A method for transmitting pilots in a wireless communication system comprising:

determining a frequency selectivity of a user; and

selecting a pilot pattern for the user based upon a frequency selectivity threshold.

16. The method of claim 15, wherein determining comprises determining based upon a velocity of the user.

17. The method of claim 16, wherein selecting comprises selecting based upon the velocity with respect to the frequency selectivity threshold.

18. The method of claim 17, wherein selecting comprises selecting a number of pilots based upon the velocity.

19. The method of claim 15, wherein determining comprises determining based upon a delay spread of the user.

20. The method of claim 15, wherein determining comprises determining based upon a dopier spread.