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US-12621075-B2 - Systems and methods for detection of LTE ingress using LTE signal properties

US12621075B2US 12621075 B2US12621075 B2US 12621075B2US-12621075-B2

Abstract

A communication device in a communication network includes at least one processor. The at least one processor is configured to at least one processor configured to search a spectrum of the communication network using a Long Term Evolution Primary Synchronization/Secondary Synchronization Signals (LTE PSS/SSS), estimate the LTE interference using cell specific reference signals for Down Link (DL) when the LTE PSS/SSS signal is detected, and utilize LTE cell specific reference signals (CRS) and feed the equalized signal to a Data Over Cable Service Interface Specification (DOCSIS) Physical Layer (PHY) engine.

Inventors

  • Balkan Kecicioglu
  • Vaibhav Singh

Assignees

  • CABLE TELEVISION LABORATORIES, INC

Dates

Publication Date
20260505
Application Date
20230616

Claims (19)

  1. 1 . A method for detecting an ingressing wireless signal on a wired communication medium configured to transmit a wired signal over a communication network, the method performed by at least one measurement device including an adaptive filter, the method comprising: tracking the ingressing wireless signal on the wired communication medium; detecting, from the tracked ingressing wireless signal, at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS); estimating, after detecting at least one of the PSS and the SSS, an interference level of a frequency response of the tracked ingressing wireless signal using downlink reference signals of the ingressing wireless signal; and filter the transmitted wireless signal to reject the estimated interference level of the frequency response.
  2. 2 . The method of claim 1 , wherein tracking the ingressing wireless signal is performed continuously.
  3. 3 . The method of claim 1 , wherein the ingressing wireless signal is at least one of a long term evolution (LTE) signal, a new radio (NR) signal, an NR-U signal, a licensed assisted access (LAA) signal, and a 5G signal, and wherein the downlink reference signals are cell specific reference signals (CRS) including at least one of an LTE frame boundary, a cell ID, and a system bandwidth.
  4. 4 . The method of claim 3 , wherein the filtering removes the interference based on at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), an orthogonal frequency division multiplexing (OFDM) symbol duration, and the downlink CRS.
  5. 5 . The method of claim 3 , wherein values of the CRS are based on OFDM symbols.
  6. 6 . The method of claim 1 , further comprising searching a spectrum of the communication network for the PSS and/or the SSS.
  7. 7 . The method of claim 6 , wherein the spectrum includes a band ranging from 600 MHz to 850 MHz.
  8. 8 . The method of claim 7 , wherein the spectrum includes a band ranging from 700 MHz to 800 MHz.
  9. 9 . The method of claim 8 , wherein the spectrum includes a band ranging from 750 MHz to 790 MHz.
  10. 10 . The method of claim 1 , wherein the wired communication medium is a cable plant.
  11. 11 . The method of claim 1 , wherein the communication network utilizes a Data Over Cable Service Interface Specification (DOCSIS) protocol.
  12. 12 . A method for detecting an ingressing wireless signal on a wired communication medium configured to transmit a wired signal over a communication network, the method performed by at least one measurement device including an adaptive filter, the method comprising: tracking a detected presence of the ingressing wireless signal on the wired communication medium; estimating an interference level of a frequency response of the detected presence using downlink reference signals of the ingressing wireless signal; filter the transmitted wireless signal to reject the estimated interference level of the frequency response; and extracting a frequency response of the interference using a first three OFDM symbols of a cell specific reference signal (CRS), wherein the ingressing wireless signal is at least one of a long term evolution (LTE) signal, a new radio (NR) signal, an NR-U signal, a licensed assisted access (LAA) signal, and a 5G signal, and wherein the downlink reference signals are CRS (i) including at least one of an LTE frame boundary, a cell ID, and a system bandwidth, and (ii) having values based on at least the first three OFDM symbols.
  13. 13 . The method of claim 12 , further comprising equalizing the extracted frequency response.
  14. 14 . A method for detecting an ingressing wireless signal on a wired signal of a wired communication medium of a communication network, comprising: searching a spectrum of the communication network for signal properties of the ingressing wireless signal; detecting a presence of the signal properties; estimating, after the step of detecting, an interference level of the ingressing wireless signal using reference signals of the ingressing wireless signal type; and equalizing the wired signal to remediate the estimated interference level.
  15. 15 . The method of claim 14 , wherein the ingressing wireless signal is at least one of a long term evolution (LTE) signal, a new radio (NR) signal, an NR-U signal, a licensed assisted access (LAA) signal, and a 5G signal, and wherein the reference signals are cell specific reference signals (CRS) including at least one of an LTE frame boundary, a cell ID, and a system bandwidth.
  16. 16 . The method of claim 15 , wherein the signal properties include at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), an orthogonal frequency division multiplexing (OFDM) symbol duration, and the CRS for a downlink.
  17. 17 . The method of claim 14 , further comprising equalizing feeding the equalized signal to a data over cable service interface specification (DOCSIS) Physical layer (PHY) engine.
  18. 18 . A method of remediating an ingressing wireless signal of a wireless interference source from a wired signal of a wired communication medium of a communication network, comprising: searching a spectrum of the communication network for the ingressing wireless signal from using signal properties of a communication protocol of the ingressing wireless signal; detecting a presence of the ingressing wireless signal on the wired signal; estimating an interference level of the detected ingressing wireless signal using reference signals of the wireless interference source; equalizing the wired signal to configured to remediate the estimated interference level; and transmitting the equalized signal over the wired communication medium.
  19. 19 . The method of claim 18 , wherein the communication protocol of the ingressing wireless signal is cellular protocol, and wherein the communication network utilizes a data over cable service interface specification (DOCSIS) protocol.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a divisional application of U.S. application Ser. No. 17/085,614, filed Oct. 30, 2020, which application is a continuation of U.S. application Ser. No. 16/039,192, filed Jul. 18, 2018, which prior application claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 62/533,862, filed Jul. 18, 2017, both of which are incorporated herein by reference in their entireties. BACKGROUND The field of the disclosure relates generally to coexisting communication platforms, and more particularly, to management of communication systems through detection and remediation of an ingress of one platform onto another platform causing an interference. Long Term Evolution (LTE) transmission in certain bands (for example 600, 700 and 850 MHz bands) can interfere with a DOCSIS signal, degrading the signal quality to the point that a portion of DOCSIS spectrum could be unusable. In a real-world case, a Multiple System Operator (MSO) had to abandon operation of cable channel 116 and 117 due to LTE interference from a mobile operator's LTE Band 13. Therefore, it is important to cable system operations to detect and also mitigate LTE ingress interference. Conventionally, detection of LTE ingress interference is performed passively by monitoring the impact to DOCSIS performance metrics. Conventional communication systems include wired networks (e.g., cable, fiber optic, hybrid fiber coaxial (HFC), etc.) and wireless technologies (e.g., Wi-Fi, Bluetooth, Zigbee, Long Term Evolution (LTE), etc.). Some HFC networks include Wi-Fi and/or small cell LTE within the communication system of the network. However, transmissions from a mobile macrocell or a macro base station (Macro BS) within the operational vicinity of the HFC network may interfere with the cable television (CATV) signals throughout the network. An illustrative example of such interference is shown below with respect to FIG. 1. FIG. 1 illustrates a conventional LTE channel plan 10. As illustrated in FIG. 1, LTE channel plan 10 includes an LTE band plan 12, and is superimposed on a CATV sub-band 14. In this example, LTE band plan 12 is shown to include the 700 MHz range, and CATV sub-band 14 is shown to include channel 108 (696-702 MHz) through channel 126 (804-810 MHz). From the example illustrated in FIG. 1, it can be seen how interference occurs when the 700 MHz LTE frequencies ingress the cable plant on CATV channels. Because the 700 MHz modulation is digital, the interference will appear as an increase in the noise floor in the CATV program or data channel. That is, LTE in the 700 MHz range is a major source of interference for the cable signal. This interference may drive error rates beyond a tolerable level, and further cause the collapse of digital programming. In one instance, a multiple-system operator (MSO) was forced to abandon cable channels 116 and 117 due to interference 16 from a wireless LTE mobile network operator (MNO) downlink (DL). FIG. 2 is a schematic illustration depicting a conventional cable network 20 operating within the vicinity of a macro base station 22. In this example, macro base station 22 represents a transmitting portion of a wireless LTE MNO, and conventional cable network 20 is an HFC network operable to provide video, voice, and data services to subscribers. Network 20 includes a master headend/hub 24, a node 26, and at least one long fiber or cable 28 (e.g., up to 80 km) connecting headend/hub 24 with node 26. In some examples, headend/hub 24 includes a plurality of headends and/or hubs connected over an optical link (not shown). In this example, headend/hub 24 is in operable communication with at least one satellite earth station/dish 30, the Internet 32, and the public switched telephone network (PSTN) 34. Node 26 connects with a plurality of trunk cables 36 (three shown in this example) that each service a respective service area 38. Each service area 38 may service between 125 and 500 end users 40 (e.g., homes/residences or businesses) that each include at least one cable modem (CM) (not separately shown) connected to a respective trunk cable 36 by one or more drop cables 42. In operation of network 20, macro base station 22 transmits an LTE signal 44 within the vicinity of a portion 46 of trunk cable 36(1), and thereby introduces interference into the cable signal carried along trunk cable 36(1) that affects all CMs 40 from the point of interference or leakage (i.e., portion 46) onwards (e.g., service area 38(1)). This LTE interference poses an additional problem with respect to inclusion of a small cell base station 48 within the service area 38(1) as another type of end user. Small cell base station 48 is considered “small” with respect to macro base station 22 because small cell base station 48 generally includes a low-powered cellular radio access node having a range of 10 meters to a few kilometers, which is a considerably shorter range than tha