Modulation identification device

• US 7,260,156 B2
• Filed: 06/26/2001
• Issued: 08/21/2007
• Est. Priority Date: 06/28/2000
• Status: Expired due to Fees

• Current Assignee: Sony Deutschland GmbH (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Deutschland GmbH (Sony Group Corp.)
• Inventors: Ratni, Mohamed, Krupezevic, Dragan, Zaragoza, Robert Morelos, Brankovic, Veselin
• Primary Examiner(s): Payne; David C.
• Assistant Examiner(s): File; Erin M.
• Application Number:
  US09/892,919
• Publication Number:
  US 20020041639A1
• Time in Patent Office: 2,247 Days
• Field of Search: 375/295, 375/321, 375/377, 455/67, 455/415, 455/463, 455/67.1, 455/67.4, 455/703, 327/291, 332/106, 341/20, 341/173
• US Class Current: 375/295
• CPC Class Codes: H04B 1/16 Circuits
• CPC Class Codes: H04L 27/0012 arrangements for identifying the type of modulation
• CPC Class Codes: H04L 27/18 Phase-modulated carrier systems, i.e. using phase-shift keying H04L27/32 takes precedence
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems

Abstract

A modulation identification device can be used for detecting the modulation type of a wirelessly transmitted and modulated RF signal without a-priori information on the kind of modulation used. The modulation identification device (1) comprises a n-port junction (17), n being an integer equal to or larger than three. The n-port junction (17) is supplied with the modulated RF signal (2) and a second RF signal (3) from a local oscillator. The n-port junction (17) outputs at least one third RF signal to at least one power detector (18). A signal processing unit (6) processes the power detected output of the n-port junction (17) to generate at least one flag (10) indicating the identified modulation type.

Claims

1. A modulation identification device having a first input for a modulated RF signal to be identified, a second input for a second RF signal having a frequency essentially corresponding to a carrier frequency of the modulated RF signal and at least one output for a flag indicating a modulation identified, wherein the device comprises:

a n-port junction, n being an integer equal to or larger than three, being supplied with the modulated RF signal and the second RF signal and outputting at least one third RF signal to at least one power detector;

a signal processing unit for processing an output of the power detector to generate the at least one flag; and

a unit for averaging at least one branch of the output of the power detector over a predetermined number of symbols before the output of the power detector is supplied to the signal processing unit.

2. The modulation identification device according to claim 1, wherein the signal processing unit comprises at least one comparison unit for comparing a processed output of the at least one power detector with at least one predetermined threshold.

3. The modulation identification device according to claim 1, wherein the signal processing unit is provided with an input for a-priori information on a symbol duration of the modulated RF signal.

4. A software defined radio device, comprising a modulation identification device according to claim 1.

5. A modulation identification device having a first input for a modulated RF signal to be identified, a second input for a second RF signal having a frequency essentially corresponding to a carrier frequency of the modulated RF signal and at least one output for a flag indicating a modulation identified, wherein the device comprises:

a n-port junction, n being an integer equal to or larger than three, being supplied with the modulated RF signal and the second RF signal and outputting at least one third RF signal to at least one power detector; and

a signal processing unit for processing the output of the power detector to generate the at least one flag, wherein

the signal processing unit comprises at least one comparison unit for comparing a processed output of the at least one power detector with at least one predetermined threshold, and

the at least one predetermined threshold is calculated on a basis of at least one relative power ratio, the relative power ratio being a ratio of a current processed output of the at least one power detector and an average processed output of the at least one power detector.

6. A modulation identification device having a first input for a modulated RF signal to be identified, a second input for a second RF signal having a frequency essentially corresponding to a carrier frequency of the modulated RF signal and at least one output for a flag indicating a modulation identified, wherein the device comprises:

a n-port junction, n being an integer equal to or larger than three, being supplied with the modulated RF signal and the second RF signal and outputting at least one third RF signal to at least one power detector; and

a signal processing unit for processing an output of the power detector to generate the at least one flag, wherein

the signal Processing unit comprises at least one comparison unit for comparing a processed output of the at least one power detector with at least one predetermined threshold, and

the signal processing unit comprises at least one counter for counting a number (n_hit) of hits for which the processed output of the at least one power detector satisfies at least one predetermined comparison condition, the at least one predetermined comparison condition being based on the at least one predetermined threshold.

7. The modulation identification device according to claim 6, wherein the signal processing unit comprises a calculation unit for calculating a probability for a modulation to be identified on a basis of the number of hits.

8. The modulation identification device according to claim 7, wherein the signal processing unit is configured to output a flag for an identified modulation in case a corresponding calculated probability exceeds a predetermined probability threshold.

9. A method for identifying a modulation of a wirelessly transmitted modulated RF signal, the method comprising the following steps:

supplying the modulated RF signal and a second RF signal having a frequency essentially corresponding to a carrier frequency of the modulated RF signal respectively to an input of a n-port junction outputting at least one output RF signal, n being an integer larger than three; and

signal processing the at least one output RF signal of the n-port junction to generate at least one flag indicating the identified modulation of the modulated RF signal, wherein

at least one branch of the output of the n-port junction is averaged over a predetermined number of symbols.

10. The method according to claim 9, wherein the signal processing comprises comparing a processed output of the n-port junction with at least one predetermined threshold.

11. A method for identifying a modulation of a wirelessly transmitted modulated RF signal, the method comprising:

supplying the modulated RF signal and a second RF signal having a frequency essentially corresponding to a carrier frequency of the modulated RF signal respectively to an input of a n-port junction outputting at least one output RF signal, n being an integer larger than three; and

signal processing the at least one output RF signal of the n-port junction to generate at least one flag indicating the identified modulation of the modulated RE signal, wherein

the signal Processing comprises comparing a processed output of the n-port junction with at least one predetermined threshold, and

the signal processing furthermore comprises counting a number of hits for which the processed output of the n-port junction satisfies at least one predetermined comparison condition.

12. The method according to claim 11, wherein the signal processing further comprises calculating a probability for a modulation to be identified on the basis of the number of hits.

13. The method according to claim 12, wherein the signal processing further comprises outputting a flag for an identified modulation in case a corresponding calculated probability exceeds a predetermined probability threshold.