Subscriber line tester

• US 6,205,202 B1
• Filed: 03/15/1999
• Issued: 03/20/2001
• Est. Priority Date: 03/23/1998
• Status: Expired due to Fees

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Yokogawa Electric Corporation
• Inventors: Shimabara, Norio, Yoshida, Takashi
• Primary Examiner(s): NGUYEN, DUC MINH
• Application Number:
  US09/270,252
• Time in Patent Office: 736 Days
• Field of Search: 375/226-227, 379/3, 379/5-6, 379/21-22, 379/24-26, 379/27-29, 379/30, 379/32, 324/525-534, 324/539, 324/542-543
• US Class Current: 379/27.02
• CPC Class Codes: H04M 1/24 Arrangements for testing
• CPC Class Codes: H04M 3/303 and using PCM multiplexers, e.g. pair gain systems

Abstract

A subscriber line tester for communication lines that convey high speed digital data, wherein a transmission side tester is provided that divides a measuring frequency region into two or more blocks, generates multi-sine waveforms obtained by combining sine waveforms of two or more frequencies in each block, and outputs the multi-sine waveforms to the communication line; and a reception side tester is provided that measures the multi-sine waveforms in the most suitable range for each block, and synthesizes a spectrum from each spectrum obtained for each block, so that high speed communication and long time period measurement are improved.

Claims

1. A subscriber line tester for communication lines that convey high speed digital data, said tester comprising:

a transmission side tester comprising;

a signal generator connected to one end of a communication line;

a first controller for controlling said signal generator;

means for dividing a measuring frequency range into two or more blocks;

means for generating a plurality of multi-sine waveforms obtained by combining sine waves of two or more frequencies in each block; and

means for outputting said plurality of multi-sine waveforms to said communication line; and

a reception side tester comprising;

an analog to digital converter connected to another end of said communication line for receiving and converting to digital signals said plurality of multi-sine waveforms outputted by said means for outputting of said transmission side tester;

a memory for storing a plurality of spectra of different multi-sine waveforms;

a second controller for controlling said analog to digital converter and said memory;

means under control of said second controller for processing said digital signals representing said plurality of multi-sine waveforms in a most suitable range for each block; and

means for synthesizing a spectrum from each of said digital signal representing said plurality of multi-sine waveforms obtained for each of said blocks which is compared with said spectra stored in said memory, thereby to test said line.

2. A subscriber line tester for communication lines that convey high speed data, said tester comprising:

a display having a screen means for causing said display to display measured noise characteristics of a communication line on said screen; and

means for over-writing a typical noise spectrum of said screen of said display.

3. The tester of claim 2, further comprising means for over-writing two or more types of noise spectrum on said screen of said display.

4. The tester of claim 3, further-comprising means for displaying two or more types of noise spectrum by identifying noise spectrum by color.

5. The tester of claim 2, further comprising means for over-writing one type of noise spectrum on a screen of a display;

and means for switching each type of noise spectrum by operating an input means.

6. A subscriber line tester for communication lines that convey high speed digital data, said tester comprising:

a transmission side tester comprising;

a signal generator connected to one end of a communication line;

a first controller for controlling said signal generator;

means for dividing a measuring frequency region into two or more blocks;

means for generating multi-sine waveforms obtained by combining sine waves of two or more frequencies in each block; and

means for outputting said multi-sine waveforms to said communication line; and

a reception side tester comprising;

an analog to digital converter connected to another end of said communication line;

a memory;

a second controller for controlling said analog to digital converter and said memory;

means for measuring said multi-sine waveforms in a most suitable measuring range for each block; and

means for synthesizing a spectrum for each spectrum obtained for each of said blocks;

wherein

said multi-sine waveform generating means comprises

means for generating multi-sine waveforms in the form of repeated waveforms; and

further comprising

means for applying Fourier transform processing to said multi-sine waveforms after subjecting said multi-sine waveforms to averaging.

7. The tester of claim 6, further comprising means for synchronizing said transmission side tester and said reception side tester using a circuit in each of said transmission side tester and said reception side tester thereby to implement communication through said communication line.

8. The tester of claim 6, further comprising means for overwriting a typical noise spectrum on a screen of a display where measured noise characteristics of said communication line is displayed.

9. The tester of claim 6, wherein said reception side tester further comprises means for determining data required for Fourier transform processing for maximum values within a preset interval;

and means for accummulating in turn noise spectrum obtained by applying Fourier transform processing to said data.

10. A subscriber line tester for communication lines that convey high speed digital data, said tester comprising:

a transmission side tester comprising;

a signal generator connected to one end of a communication line;

a first controller for controlling said signal generator;

means for dividing a measuring frequency region into two or more blocks;

means for generating multi-sine waveforms obtained by combining sine waves of two or more frequencies in each block; and

means for outputting said multi-sine waveforms to said communication line; and

a reception side tester comprising;

an analog to digital converter connected to another end of said communication line;

a memory;

a second controller for controlling said analog to digital converter and said memory;

means for measuring said multi-sine waveforms in a most suitable measuring range for each block; and

means for synthesizing a spectrum from each spectrum obtained for each of said blocks; and

further comprising;

means for overwriting a typical noise spectrum on a screen of a display where measured noise characteristics of said communication line is displayed.

11. The tester of claim 10, further comprising means for synchronizing said transmission side tester and said reception side tester using a circuit in each of said transmission side tester and said reception side tester thereby to implement communication through said communication line.

12. The tester of claim 10, wherein said reception side tester further comprises means for determining data required for Fourier transform processing for maximum values within a preset interval;

and means for accummulating in turn noise spectrum obtained by applying Fourier transform processing to said data.

13. The tester of claim 10, further comprising means for over-writing one or more types of noise spectrum on said screen of said display.

14. The tester of claim 10, further comprising means for over-writing one type of noise spectrum on a screen of a display;

and means for switching each type of noise spectrum by operating an input means.