Receiver, apparatus for generating despread code, and method of generating despread code

• US 20060114971A1
• Filed: 11/14/2005
• Published: 06/01/2006
• Est. Priority Date: 11/30/2004
• Status: Abandoned Application

• Current Assignee: Seiko Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Muto, Nobuo
• Application Number:
  US11/272,001
• Publication Number:
  US 20060114971A1
• Time in Patent Office: Days
• US Class Current: 375/147
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence

Abstract

A receiver receives and demodulates a transmission signal that is modulated in Phase Shift Keying modulation and Direct Sequence Spread Spectrum using a spread code. The receiver includes a signal receiving unit that receives the transmission signal and outputs a received signal; a filter unit through which the received signal outputted by the signal receiving unit passes and is outputted as an outputted signal; a base band unit that is configured to despread the outputted signal based on a corrected despread code. The corrected despread code is generated based on the spread code and a deformation position, the deformation position indicating a position in the spread code at which deformation occurs as a result of the received signal passing through the receiver filter unit.

Claims

1. A receiver that is configured to receive a transmission signal, the transmission signal being modulated in Direct Sequence Spread Spectrum using a spread code, the receiver comprising:

a signal receiving unit that is configured to receive the transmission signal and output a received signal;

a receiver filter unit through which the received signal outputted by the signal receiving unit passes and is outputted as an outputted signal; and

a base band unit that is configured to despread the outputted signal based on a corrected despread code,

the corrected despread code being generated based on the spread code and a deformation position, the deformation position indicating a position in the spread code at which deformation occurs as a result of the received signal passing through the receiver filter unit.

2. The receiver according to claim 1, further comprising

a storing unit configured to store the corrected despread code.

3. The receiver according to claim 2, further comprising

a communication unit,

wherein the receiver is configured to acquire the corrected despread code from an information providing apparatus through a network via the communication unit and store the corrected despread code in the storing unit.

4. The receiver according to claim 1, wherein

the base band unit includes a circuit that is configured to generate the corrected despread code based on the spread code and the deformation position.

5. The receiver according to claim 1, wherein

the transmission signal is a positioning signal transmitted from a satellite positioning system satellite.

6. The receiver according to claim 5, further comprising

a storing unit configured to store the corrected despread code,

the storing unit being configured to store a corrected despread code for each of satellite positioning system satellites that communicate with the receiver.

7. The receiver according to claim 1, further comprising

an A/D conversion unit that converts the outputted signal to generate a digital signal,

the base band unit being configured to despread the digital signal using the corrected despread code.

8. The receiver according to claim 1, wherein

the corrected despread code is generated by inverting a value of the spread code at the deformation position.

9. An apparatus for generating a corrected despread code to be used for demodulating a transmission signal, the transmission signal being modulated in Phase Shift Keying modulation and Direct Sequence Spread Spectrum using a spread code, the apparatus for generating a corrected despread code comprising:

a simulation signal generating unit that is configured to generate a simulation signal modulated in Phase Shift Keying modulation and Direct Sequence Spread Spectrum using the spread code;

an apparatus filter unit through which the simulation signal generated by the simulation signal generating unit passes and is outputted as an outputted simulation signal; and

a corrected despread code generating unit that is configured to compare the simulation signal and the outputted simulation signal and obtain a deformation position which indicates a position in the spread code at which deformation occurs as a result of the simulation signal passing through the apparatus filter unit, the corrected despread code generating unit being further configured to generate a corrected despread code by changing a value of the spread code at the deformation position.

10. The apparatus for generating a corrected despread code according to claim 9, wherein

the corrected despread code is generated by inverting the value of the spread code at the deformation position.

11. A method of generating a corrected despread code to be used for demodulating a transmission signal, the transmission signal being modulated in Phase Shift Keying modulation and Direct Sequence Spread Spectrum using a spread code, the method of generating a corrected despread code comprising:

generating a simulation signal modulated in Phase Shift Keying modulation and Direct Sequence Spread Spectrum using the spread code;

removing a high-frequency component from the simulation signal and generating an outputted simulation signal;

comparing the simulation signal and the outputted simulation signal and obtaining a deformation position, the deformation position indicating a position in the spread code at which deformation occurs as a result of the high-frequency component being removed from the simulation signal; and

generating a corrected despread code by changing a value of the spread code at the deformation position.

12. The method of generating a corrected despread code according to claim 11, wherein

the deformation position is obtained by a numerical analysis performed with a computer program.

13. The method of generating a corrected despread code according to claim 11, wherein

the deformation position is obtained by displaying a waveform of the simulation signal and a waveform of the outputted simulation signal.

14. The method of generating a corrected despread code according to claim 11, wherein

the transmission signal is a positioning signal transmitted from a satellite positioning system satellite, and

the corrected despread code is generated for each of a plurality of satellite positioning system satellites.

15. The method of generating a corrected despread code according to claim 11, wherein

the corrected despread code is generated by inverting the value of the spread code at the deformation position.