# US 12,278,715 B2 · Vector channel analyzer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,278,715 B2 - Document ID: US12278715B2 - Status: Granted - Kind: B2 - Application number: 18/198,366 - Filed: 2023-05-17 - Published: 2023-11-30 - Granted: 2025-04-15 - Earliest claimed: 2022-05-24 - Assignees: Astronics Test Systems, Inc. - Applicants: Astronics Test Systems, Inc. - Inventors: Gary Robert Kenworthy - Web page: https://patentgrep.com/patent/US12278715B2 ## CPC - H04L 25/0212: {of impulse response} - H04B 17/15: Performance testing - H04L 25/022: {of frequency response} - H04L 25/0226: {sounding signals per se} - H04L 25/0222: {Estimation of channel variability, e.g. coherence bandwidth, coherence time, fading frequency} - H04L 25/0228: {with direct estimation from sounding signals} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION ## Abstract A system and method for measuring characteristics of a signal transmission channel. A generator generates a defined signal as a function of user defined reference parameters, and injects the defined signal into an input of the signal transmission channel. An analyzer receives the defined signal from an output of the signal transmission channel. The analyzer also includes the user defined reference parameters, and measures a reference delay and reference frequency offset without any timing or phase reference synchronization with the generator. The analyzer computes a time-dependent (impulse response) and/or frequency-dependent (frequency response) variation of a response of the signal transmission channel relative to the reference delay and reference frequency offset. ## Claims ### Claim 1 A method for measuring characteristics of a signal transmission channel, the method comprising: receiving user defined reference parameters at a generator connectable with the signal transmission channel; receiving the user defined reference parameters at an analyzer connectable with the signal transmission channel; constructing, by the generator, a defined signal as a function of the user defined reference parameters; injecting the defined signal into an input of the signal transmission channel; receiving an output signal with the analyzer at an output of the signal transmission channel; determining a reference delay and/or a reference frequency offset for an output signal at the analyzer without any timing or phase reference connection with the generator; computing, by the analyzer, a transfer function of the signal transmission channel, represented as time-dependent and/or frequency-dependent characteristics of the signal transmission channel, calculated with respect to the reference delay and the reference frequency offset; and displaying or recording results of the computing. ### Claim 2 (depends on 1) The method of claim 1, wherein the user defined reference parameters comprise frequency span and resolution. ### Claim 3 (depends on 1) The method of claim 1, wherein the defined signal comprises a repeating fixed frame in a time domain and resulting discrete tones in a frequency domain. ### Claim 4 (depends on 1) The method of claim 1, wherein measuring the reference delay and/or the reference frequency offset comprises analysis of a cross-ambiguity function of an output signal with respect to the defined signal. ### Claim 5 (depends on 1) The method of claim 1, wherein measuring the reference delay and/or the reference frequency offset comprises a joint estimation of the reference delay and the reference frequency offset across a two-dimensional domain. ### Claim 6 (depends on 1) The method of claim 1, further comprising adjusting the reference delay according to user preference. ### Claim 7 (depends on 1) The method of claim 1, wherein a search range for the reference frequency offset is either a full range or a fixed partial range of a received signal bandwidth. ### Claim 8 (depends on 1) The method of claim 1, further comprising searching for the reference frequency offset until a predetermined match threshold is detected. ### Claim 9 (depends on 8) The method of claim 8, wherein a frequency search begins centered on a previously detected reference frequency offset. ### Claim 10 (depends on 1) The method of claim 1, wherein the reference frequency offset is fixed by a user. ### Claim 11 (depends on 1) The method of claim 1, wherein the computing, by the analyzer, the time-dependent and/or frequency-dependent characteristics comprises applying one or more mask vectors for suppressing calculation and/or display of invalid data. ### Claim 12 (depends on 1) The method of claim 1, further comprising inverting a spectrum of the output signal received by the analyzer to compensate for channel paths including spectral inversion. ### Claim 13 (depends on 1) The method of claim 1, further comprising estimating a signal-to-noise ratio (SNR) of the output signal received by the analyzer. ### Claim 14 (depends on 1) The method of claim 1, further comprising estimating a mismatch in a timing rate of a signal transmission channel receiver relative to a signal transmission channel transmitter and as affected by Doppler effect in the signal transmission channel. ### Claim 15 (depends on 14) The method of claim 14, further comprising resampling received data to compensate for a mismatched rate. ### Claim 16 (depends on 14) The method of claim 14, further comprising adjusting a sampling rate of the signal transmission channel receiver to compensate for a mismatched rate. ### Claim 17 (depends on 1) The method of claim 1, further comprising computing a baseline channel reference using at least one computational result of the analyzer while connected to a reference transmission channel, and thereafter computing channel characteristics relative to the baseline channel reference. ### Claim 18 (depends on 1) The method of claim 1, wherein displayed or recorded results comprise one or more of: an amplitude response (LogMag), a phase response, a group delay, an impulse response, a raw received signal-time-domain (oscilloscope), a raw received signal-frequency domain (spectrum analyzer), and a frequency offset. ### Claim 19 A system for measuring characteristics of a signal transmission channel, comprising: a generator configured to: generate a defined signal as a function of user defined reference parameters; and inject the defined signal into an input of the signal transmission channel; an analyzer configured to: receive the defined signal from an output of the signal transmission channel, wherein the analyzer includes the user defined reference parameters; measure a reference delay and a reference frequency offset without any timing or phase reference synchronization with the generator; and compute a time-dependent and/or a frequency-dependent variation of a response of the signal transmission channel relative to the reference delay and the reference frequency offset; and a display and/or recording device configured to receive results of the analyzer computations.