Target signal determination method and associated apparatus

• US 9,313,057 B2
• Filed: 10/26/2010
• Issued: 04/12/2016
• Est. Priority Date: 11/16/2009
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MStar Semiconductor Incorporated (MediaTek, Inc.)
• Inventors: Chuang, Ching-Hsiang, Hung, Shao-Ping, Ho, Tien-Hsin
• Primary Examiner(s): Toatley, Gregory J
• Assistant Examiner(s): SUAREZ, FELIX E
• Application Number:
  US12/912,200
• Publication Number:
  US 20110119008A1
• Time in Patent Office: 1,995 Days
• Field of Search: 702/20, 702/66, 702/73, 702/179, 702/183, 702/189, 702/193, 342/107, 342/132, 342/174, 704/219
• US Class Current: 1/1
• CPC Class Codes: G10L 25/06 the extracted parameters being correlation coefficients
• CPC Class Codes: H03L 1/00 Stabilisation of generator output against variations of physical values, e.g. power supply
• CPC Class Codes: H04L 25/065 Binary decisions

Abstract

A method and associated apparatus using delay correlation for determining whether an input signal is a target signal is provided. The method includes sampling the input signal to generate 2N sample values, the sample values having a period N, where N is a positive integer; calculating the 2N sample values to obtain a first value according to a first operation method; calculating the 2N sample values to obtain a second value according to a second operation method; obtaining a determination value according to the first value and the second value; and determining whether the input signal is the target signal according to the determination value and a threshold.

Claims

1. A method using delay correlation for determining whether an input signal is a target signal implemented in a signal receiving electronic device with a non-transitory computer-readable storage medium storing an executable program, comprising:

receiving the input signal by the signal receiving electronic device;

sampling the input signal to generate 2N sample values, wherein the period of the sample values is N, where N is a positive integer;

obtaining a first value according to a first operation method by processing the 2N sample values by the signal receiving electronic device instructed by the executable program stored in the non-transitory computer-readable storage medium;

obtaining a second value according to a second operation method by processing the 2N sample values by the signal receiving electronic device instructed by the executable program stored in the non-transitory computer-readable storage medium;

obtaining a determination value according to a ratio of the first value and the second value, wherein the determination value is a quotient of the first value divided by the second value, and the second value equals Σ

<sub>k=−

N</sub>^N-1|r(t−

N−

k)|² where r(t) is a sample value at time t; and

determining whether the input signal is the target signal or not according to the determination value and a threshold; and

continuing to receive said input signal if said input signal is determined to be said target signal, otherwise, discontinuing receipt of said input signal.

2. The method according to claim 1, wherein the first operation method comprises:

conjugating a first plurality of N sample values for obtaining N conjugate values;

multiplying the N conjugate values by a second plurality of N sample values one-to-one; and

summing up for obtaining the first value.

3. The method according to claim 2, wherein the second operation method comprises:

multiplying the 2N sample values by their conjugations; and

summing up for obtaining the second value.

4. The method according to claim 3, wherein the second operation method further comprises:

multiplying the first plurality of N sample values by their conjugations;

summing up and square rooting for obtaining a first square root;

multiplying the second plurality of N sample values by their conjugations;

summing up and square rooting for obtaining a second square root; and

multiplying the first square root with the second square root for obtaining the second value.

5. The method according to claim 1, wherein the step of determining further comprises:

determining the input signal as the target signal when the determination value is larger than or equal to the threshold; and

determining the input signal not the target signal when the determination value is larger than or equal to the threshold.

6. The method according to claim 1, wherein the sample values are complex.

7. The method according to claim 1, wherein the determination value is between zero (0) and one (1).

8. The method according to claim 7, wherein the threshold is between zero (0) and one (1).

9. A communication apparatus for receiving an input signal and using delay correlation for determining whether the input signal is a target signal, comprising:

a receiver, for receiving the input signal;

a sampling circuit, for sampling the input signal to generate 2N sample values, wherein the period of the 2N sample values is N, where N is a positive integer;

a delaying circuit, for delaying a first plurality of N sample values to output N delayed sample values, wherein the first plurality of N sample values is within the 2N sample values;

a conjugate multiplier, for conjugately multiplying the N delayed sample values with the first plurality of N sample values to generate a plurality of conjugate multiplying values;

a calculation apparatus, coupled to the conjugate multiplier, for calculating the conjugate multiplying values to obtain a determination value; and

a determination apparatus, coupled to the calculation apparatus, for determining whether the input signal is the target signal or not according to the determination value and a threshold;

wherein the determination value is the quotient of a first value divided by a second value, and the second value equals Σ

<sub>k=−

N</sub>^N-1|r(t−

N−

k)|² where r(t) is a sample value at time t;

wherein the first value is obtained from the 2N sample values according to a first operation method, and the second value is obtained from the same 2N sample values according to a second operation method

wherein said communication apparatus continues to receive said input signal if said determination apparatus determines said input signal is said target signal, and said communication apparatus discontinues receiving said input signal if said determination apparatus determines said input signal is not said target signal.

10. The apparatus according to claim 9, wherein the conjugate multiplier generates a first plurality of conjugate multiplying values by multiplying the N delayed sample values by one-to-one conjugations with the first plurality of N sample values;

and the calculation apparatus calculates the first plurality of conjugate multiplying values to obtain the first value.

11. The apparatus according to claim 10, wherein the conjugate multiplier further generates a second plurality of conjugate multiplying values by multiplying the 2N sample values by their conjugations one-to-one, and the calculation apparatus calculates the second plurality of conjugate multiplying values to obtain the second value.

12. The apparatus according to claim 10, wherein

the conjugate multiplier multiplies the first plurality of N sample values by their conjugations one-to-one to obtain a first set of N conjugate multiplying values, and multiplies a second plurality of N sample values within the 2N sample values by their conjugations one-to-one to obtain a second set of N conjugate multiplying values, and

the calculation apparatus sums up the first set of N conjugate multiplying values and calculates their square roots to obtain a first square root value, sums up the second set of N conjugate multiplying values and calculates their square roots to obtain a second square root value, and multiplies the first square root value by the second square root value to obtain the second value, or the calculation sums up the first set of N conjugate multiplying values, sums up the second set of N conjugate multiplying values, and square roots the product of them to obtain the second value.

13. The apparatus according to claim 9, wherein the conjugate multiplier comprises

a conjugate convertor, for conjugating the 2N sample values to output corresponding 2N conjugate values;

and

a multiplier, for receiving the 2N sample values, the 2N conjugate values and the N delayed sample values, multiplying the N conjugate values within the 2N conjugate values by the N delayed sample values one-to-one to output a first set of conjugate multiplying values, and multiplying the 2N sample values by the 2N conjugate values one-to-one to output a second set of conjugate multiplying values;

wherein the calculation apparatus calculates the first set of conjugate multiplying values and the second set of conjugate multiplying values to obtain the determination value.

14. The apparatus according to claim 9, wherein the conjugate multiplier comprises

a conjugate convertor, for conjugating the 2N sample values and the N delayed sample values respectively to output corresponding 2N conjugate values and N conjugate delayed values;

and

a multiplier, for receiving the 2N sample values, the 2N conjugate values and the N conjugate delayed values, multiplying the first plurality of N sample values by the N conjugate delayed values one-to-one to output a first set of conjugate multiplying values, and multiplying the 2N sample values by the 2N conjugate values one-to-one to output a second set of conjugate multiplying values;

wherein the calculation apparatus calculates the first set of conjugate multiplying values and the second set of conjugate multiplying values to obtain the determination value.

15. The apparatus according to claim 9, wherein the conjugate multiplier comprises

a conjugate convertor, for conjugating the 2N sample values and the N delayed sample values respectively to output corresponding 2N conjugate values and N conjugate delayed values;

and

a multiplier, for receiving the first plurality of N sample values, a first plurality of N conjugate values, the N delayed sample values, and the N conjugate delayed values, for multiplying the first plurality of N conjugate delayed values by the N sample values one-to-one to output a first set of conjugate multiplying values, for multiplying the N sample values by the first plurality of N conjugate values one-to-one to output a second set of conjugate multiplying values, and for multiplying the N delayed sample values by the N conjugate delayed values one-to-one to output a third set of conjugate multiplying values, wherein the first plurality of N conjugate values is within the 2N conjugate values;

wherein the calculation apparatus calculates the first set of conjugate multiplying values, the second set of conjugate multiplying values, and the third set of conjugate multiplying values to obtain the determination value.

16. The apparatus according to claim 9 wherein the conjugate multiplier comprises

a conjugate convertor, for conjugating the 2N sample values and the N delayed sample values respectively to output corresponding 2N conjugate values and N conjugate delayed values;

and

a multiplier, for receiving the first plurality of N sample values, a first plurality of N conjugate values, the N delayed sample values, and the N conjugate delayed values, for multiplying the N delayed sample values by the first plurality of N conjugate values one-to-one to output a first set of conjugate multiplying values, for multiplying the N sample values by the first plurality of N conjugate values one-to-one to output a second set of conjugate multiplying values, and for multiplying the N delayed sample values by the N conjugate delayed values one-to-one to output a third set of conjugate multiplying values, wherein the first plurality of N conjugate values is within the 2N conjugate values;

wherein the calculation apparatus calculates the first set of conjugate multiplying values, the second set of conjugate multiplying values, and the third set of conjugate multiplying values to obtain the determination value.

17. The apparatus according to claim 9, wherein the determination value is between zero (0) and one (1).

18. The apparatus according to claim 17, wherein the threshold is between zero (0) and one (1).

19. The apparatus according to claim 9, wherein the sample values are complex.