Adaptive antenna array and method for control thereof

• US 6,441,786 B1
• Filed: 07/20/2001
• Issued: 08/27/2002
• Est. Priority Date: 07/20/2001
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Michels, James P., Jasper, Steven C., Oros, Nicholas C., Birchler, Mark Allen
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US09/909,602
• Time in Patent Office: 403 Days
• Field of Search: 342/383, 342/380
• US Class Current: 342/383
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H04B 7/0842 Weighted combining

Abstract

A method for controlling an adaptive antenna array (50) is provided and includes receiving a plurality of signals, each signal including a series of signal data symbols (42) and signal non-data symbols (38, 40) divided into symbol transmission units with the signal non-data symbols (38, 40) disposed among the signal data symbols (42) in each unit and each signal related to the other signals of the plurality of signals as reflections of an original signal. The method also includes separating the signal non-data symbols (38, 40) from the signal data symbols (42), and comparing the signal non-data symbols (38, 40) to a set of known non-data symbols. The method further includes determining a set of weights according to the comparison of the signal non-data symbols (38, 40) to the set of known non-data symbols, the weights to be combined with the signal data values (42) to limit the effect of interference on the signal data symbols (42). An adaptive antenna array (50) is also provided including a weight calculator (62) including a program which controls the weight calculator (62) to perform the comparing (88, 90) and determining steps (94) of the method discussed above.

Claims

1. A method comprising the steps of:

receiving a plurality of signals, wherein each signal comprises an original signal, a summation of a plurality of reflections of the original signal, or a summation of the original signal and the plurality of reflections of the original signal, each of the plurality of received signals including a series of signal data symbols and signal non-data symbols with the signal non-data symbols disposed among the signal data symbols;

separating the signal non-data symbols from the signal data symbols;

comparing the signal non-data symbols to a set of known non-data symbols; and

determining a set of weights according to the comparison of the signal non-data symbols to the set of known non-data symbols, the weights to be combined with more than one of the plurality of signals to limit the effect of interference on the signal data symbols.

2. The method according to claim 1, wherein each of the signal non-data symbols and the known non-data symbols has a value and the comparison step comprises the steps of:

determining an estimated value corresponding to each of the signal non-data symbols using the known non-data symbol values; and

comparing the signal non-data symbol value and the corresponding estimated value for each of the signal non-data symbols.

3. The method according to claim 2, wherein the step of determining an estimated value comprises the step of combining the known non-data symbol values with a set of fading gains which are a function of Doppler and delay spreads of the received signals.

4. The method according to claim 2, wherein the step of determining an estimated value comprises the step of combining the known non-data symbol values with a set of fading gains which are a function of Doppler and delay spreads for the adaptive antenna array.

5. The method according to claim 4, wherein the step of determining an estimated value comprises the step of multiplying the known non-data symbol values by the fading gains.

6. The method according to claim 2, wherein the step of comparing the estimated values comprises the step of determining the differences between each of the signal non-data symbol values and its corresponding estimated value.

7. The method according to claim 6, wherein the step of determining the weights comprises the step of determining an interference-plus-noise covariance matrix according to the differences between each of the signal non-data symbol values and its corresponding estimated value.

8. A method for controlling an adaptive antenna array including a plurality of antenna elements, the method comprising the steps of:

receiving a plurality of signals, each signal including a series of signal data symbols and signal pilot symbols with the signal pilot symbols disposed among the signal data symbols and each symbol having a value, and wherein each signal comprises an original signal, a summation of a plurality of reflections of the original signal, or a summation of the original signal and the plurality of reflections of the original signal;

separating the signal pilot symbols from the signal data symbols;

determining an estimated value corresponding to each of the signal pilot symbols using a set of known pilot symbols with each pilot symbol having a value;

determining the difference between the signal pilot symbol value and its corresponding estimated value for each of the signal pilot symbols; and

determining a set of weights according to the differences between each of the signal pilot symbol values and its corresponding estimated value to limit the effect of interference on the signal data symbols.

9. A method for controlling an adaptive antenna array including a plurality of antenna elements, the method comprising the steps of:

receiving a plurality of signals, each signal including a series of signal data symbols and signal pilot symbols with the signal pilot symbols disposed among the signal data symbols and each symbol having a value, and each signal related to the other signals of the plurality of signals as reflections of an original signal;

separating the signal pilot symbols from the signal data symbols;

determining an estimated value corresponding to each of the signal pilot symbols using a set of known pilot symbols with each pilot symbol having a value;

determining the difference between the signal pilot symbol value and its corresponding estimated value for each of the signal pilot symbols; and

determining a set of weights according to the differences between each of the signal pilot symbol values and its corresponding estimated value to limit the effect of interference on the signal data symbols.

10. The method according to claim 9, wherein the step of determining an estimated value comprises the step of multiplying the set of known pilot symbol values by a set of fading gains which are a function of Doppler and delay spreads for the adaptive antenna array.

11. The method according to claim 9, wherein the step of determining the weights comprises the step of determining an interference-plus-noise covariance matrix according to the differences between each of the signal pilot symbol values and its corresponding estimated value.

12. The method according to claim 11, wherein the step of determining an interference-plus-noise covariance matrix comprises determining the product of the equation:

13. The method according to claim 9, wherein:

the signal pilot symbols and signal data symbols comprise a plurality of sets of signal pilot symbols and a plurality of sets of signal data symbols, each set of signal pilot symbols corresponding to one of the plurality of sets of signal data symbols;

the steps of determining an estimated value and determining the difference between each of the signal pilot symbol values and its corresponding estimated value is performed separately for each set of signal pilot symbols; and

the step of determining a set of weights is performed for each signal data symbol in one of the sets of signal data symbols using the difference calculated for the set of pilot symbols to which corresponds to the one of the sets of signal data symbols.

14. A weight calculator for use in a system wherein signals are transmitted between communication devices as a plurality of signals, each signal including a series of signal data symbols and signal non-data symbols divided into symbol transmission units with the signal non-data symbols disposed among the signal data symbols in each unit and wherein each signal comprises an original signal, a summation of a plurality of reflections of the original signal, or a summation of the original signal and the plurality of reflections of the original signal, the weight calculator comprising:

a processor including a program which controls the processor (i) to receive the signal non-data symbols which have been separated from the signal data symbols;

(ii) to compare the signal non-data symbols to a set of known non-data symbols; and

(iii) to determine a set of weights according to the comparison of the signal non-data symbols to the set of known non-data symbols, the weights to be combined with the signal data values to limit the effect of interference on the signal data symbols.

15. The weight calculator according to claim 14, wherein each of the signal non-data symbols and the known non-data symbols has a value, and the program further controls the processor (i) to determine an estimated value corresponding to each of the signal non-data symbols using the known non-data symbol values, and (ii) to compare the signal non-data symbol value and the corresponding estimated value for each of the signal non-data symbols.

16. The weight calculator according to claim 15, wherein the program further controls the processor to combine the known non-data symbol values with a set of fading gains which are a function of Doppler and delay spreads for the adaptive antenna array to determine an estimated value corresponding to each of the signal non-data symbols using the known non-data symbol values.

17. The weight calculator according to claim 16, wherein the program further controls the processor to multiply the known non-data symbol values by the set of fading gains to determine an estimated value corresponding to each of the signal non-data symbols using the known non-data symbol values.

18. The weight calculator according to claim 15, wherein the program further controls the processor to determine the differences between each of the signal non-data symbol values and its corresponding estimated value to compare the signal non-data symbols to a set of known non-data symbols.

19. The weight calculator according to claim 18, wherein the program further controls the processor to determine an interference-plus-noise covariance matrix according to the differences between each of the signal non-data symbol values and its corresponding estimated value to determine the weights.