Systems and methods for loop length and bridged tap length determination of a transmission line
View Patent ↗Through the use of a least squares minimization concept, the loop length, the number of bridged taps and length of the bridged taps on a transmission line can be determined from readily available modem data. In particular, the loop length, the number of bridge taps and the length of bridged taps can be estimated by comparing a measured frequency domain channel impulse response of the transmission line to a model of a loop that is comprised of multiple sections and multiple bridge taps.
1. A method to estimate a loop length of a transmission line comprising:
estimating a channel transfer function using one or more signals from an initialization, the initialization occurring between a first broadband multicarrier modem on a first end of the transmission line and a second broadband multicarrier modem on a second end of the transmission line, the one or more signals from the initialization having been transmitted or received using a multiplicity of discrete frequency carriers;
determining a theoretical channel transfer function of the transmission line;
comparing, by a controller, the theoretical channel transfer function and the estimated channel transfer function; and
determining the estimated loop length of the transmission line based upon said comparison,
wherein the theoretical transfer function has as an input a parameter related to a gauge of the transmission line.
2. The method of claim 1 , wherein the estimating of the channel transfer function uses a REVERB signal.
3. The method of claim 1 , further comprising estimating a bridged tap length.
4. The method of claim 1 , further comprising outputting the estimated loop length.
5. The method of claim 1 , wherein the estimated channel transfer function includes multiple sections with varying gauges.
6. The method of claim 1 , wherein the theoretical channel transfer includes multiple sections with varying gauges.
7. The method of claim 1 , wherein the method is performed on at least one of a single program general purpose computer, a program general purpose computer, a special purpose computer, a programmed microprocessor, a microcontroller and peripheral integrated circuit element, an ASIC or other integrated circuit, a digital signal processor, a hard wired electronic or logic circuit, a discrete element circuit, a programmable logic device, a PLD, a PLA, an FPGA, a PAL, and a modem.
8. The method of claim 1 , wherein the one or more signals utilize frequency carriers of a DSL system.
9. The method of claim 1 , wherein the discrete frequency carriers are tones that are multiples of 4312.5 Hz.
10. A non-transitory computer readable information storage media having stored thereon instructions, that if executed by a processor, cause to be performed the steps of claim 1 .
11. A loop length estimation system comprising:
a controller; and
a loop length output device capable of:
estimating a channel transfer function using one or more signals from an initialization, the initialization occurring between a first broadband multicarrier modem on a first end of a transmission line and a second broadband multicarrier modem on a second end of the transmission line, the one or more signals from the initialization having been transmitted or received using a multiplicity of discrete frequency carriers;
determining a theoretical channel transfer function of the transmission line;
comparing the theoretical channel transfer function and the estimated channel transfer function; and
determining an estimated loop length of the transmission line based upon said comparison,
wherein the theoretical transfer function has as an input a parameter related to a gauge of the transmission line.
12. The system of claim 11 , wherein the estimating of the channel transfer function uses a REVERB signal.
13. The system of claim 11 , further capable of estimating a bridged tap length.
14. The system of claim 11 , further capable of outputting the estimated loop length.
15. The system of claim 11 , wherein the estimated channel transfer function includes multiple sections with varying gauges.
16. The system of claim 11 , wherein the theoretical channel transfer includes multiple sections with varying gauges.
17. The system of claim 11 , wherein the loop length estimation system is implemented on at least one of a single program general purpose computer, a program general purpose computer, a special purpose computer, a programmed microprocessor, a microcontroller and peripheral integrated circuit element, an ASIC or other integrated circuit, a digital signal processor, a hard wired electronic or logic circuit, a programmable logic device, a PLD, a PLA, an FPGA, a PAL, and a modem.
18. The system of claim 11 , wherein the one or more signals utilize frequency carriers of a DSL system.
19. The system, of claim 11 , wherein the discrete frequency carriers are tones that are multiples of 4312.5 Hz.