# US 11,121,850 B1 · Signal analysis method and signal analysis module > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,121,850 B1 - Document ID: US11121850B1 - Status: Granted - Kind: B1 - Application number: 16/919,753 - Filed: 2020-07-02 - Granted: 2021-09-14 - Earliest claimed: 2020-07-02 - Assignees: Rohde & Schwarz GmbH & Co. KG - Applicants: Rohde & Schwarz GmbH & Co. KG - Inventors: Michael Reinhold; Hela Jedda - Web page: https://patentgrep.com/patent/US11121850B1 ## CPC - H04L 7/0025: {interpolation of clock signal} - H04L 7/0334: {Processing of samples having at least three levels, e.g. soft decisions} - H03L 7/0814: {the phase shifting device being digitally controlled} - H04L 7/0087: {Preprocessing of received signal for synchronisation, e.g. by code conversion, pulse generation or edge detection} - H04L 7/033: using the transitions of the received signal to control the phase of the synchronising-signal-generating means, e.g. using a phase-locked loop - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H03L: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES (generation of oscillations H03B) ## Abstract A signal analysis method is described. The signal analysis method comprises: receiving an N-ary input signal, the input signal comprising a symbol sequence; determining at least two threshold transition times of the input signal within a predetermined time period, wherein the input signal respectively crosses an amplitude threshold of several predetermined amplitude thresholds at each of the threshold transition times; determining time intervals between the threshold transition times; evaluating the time intervals based on a set of predefined conditions; and assigning the threshold transition times to at least one symbol transition based on the evaluation. Further, a signal analysis module is described. ## Claims ### Claim 1 A signal analysis method, said signal analysis method comprising: receiving an N-ary input signal, said input signal comprising a symbol sequence, wherein each symbol of said symbol sequence has one of N different amplitude values, and wherein N is an integer greater than 2; determining at least two threshold transition times of said input signal within a predetermined time period, wherein said input signal respectively crosses an amplitude threshold of several predetermined amplitude thresholds at each of said threshold transition times; determining time intervals between said threshold transition times; evaluating said time intervals based on a set of predefined conditions; and assigning said threshold transition times to at least one symbol transition based on the evaluation. ### Claim 2 (depends on 1) The signal analysis method of claim 1, wherein said predetermined time period is equal to or greater than two symbol intervals. ### Claim 3 (depends on 1) The signal analysis method of claim 1, wherein said set of predefined conditions comprises a first condition, according to which a time interval between consecutive threshold transition times belonging to the same symbol transition is equal to or less than a first predefined maximum time interval. ### Claim 4 (depends on 3) The signal analysis method of claim 3, wherein said first predefined maximum time interval is equal to half a symbol interval. ### Claim 5 (depends on 3) The signal analysis method of claim 3, wherein said first predefined maximal time interval depends on a number of threshold transition times within said predetermined time period. ### Claim 6 (depends on 1) The signal analysis method of claim 1, wherein said set of predefined conditions comprises a second condition, according to which a time interval between a first threshold transition time and a last threshold transition time belonging to the same symbol transition is equal to or smaller than a second predefined maximum time interval. ### Claim 7 (depends on 6) The signal analysis method of claim 6, wherein said second predefined maximum time interval is equal to one symbol period. ### Claim 8 (depends on 6) The signal analysis method of claim 6, wherein said second predefined maximum time interval is equal to (N−2)/(N−1) symbol periods. ### Claim 9 (depends on 1) The signal analysis method of claim 1, wherein said set of predefined conditions comprises a third condition, according to which an amplitude of said input signal is monotonous over time intervals belonging to the same symbol transition. ### Claim 10 (depends on 1) The signal analysis method of claim 1, wherein at least one of a symbol value and a symbol transition time is determined based on said threshold transition times and said amplitude thresholds associated with said threshold transition times. ### Claim 11 (depends on 1) The signal analysis method of claim 1, wherein said input signal is Pulse Amplitude Modulation (PAM)-N coded. ### Claim 12 A signal analysis circuit, said signal analysis circuit comprising an input being configured to receive an input signal, said signal analysis circuit comprising a threshold circuit being configured to determine at least two threshold transition times of said input signal within a predetermined time period, wherein said input signal respectively crosses an amplitude threshold of several predetermined amplitude thresholds at each of said threshold transition times, said signal analysis circuit further comprising a processing circuit, said processing circuit being configured to determine time intervals between said threshold transition times, said processing circuit further being configured to evaluate said time intervals based on a set of predefined conditions, and said processing circuit further being configured to assign said threshold transition times to at least one symbol transition based on the evaluation. ### Claim 13 (depends on 12) The signal analysis circuit of claim 12, wherein said predetermined time period is equal to or greater than two symbol intervals. ### Claim 14 (depends on 12) The signal analysis circuit of claim 12, wherein said set of predefined conditions comprises a first condition, according to which a time interval between consecutive threshold transition times belonging to the same symbol transition is equal to or smaller than a first predefined maximum time interval. ### Claim 15 (depends on 14) The signal analysis circuit of claim 14, wherein said first predefined maximum time interval is equal to half a symbol interval. ### Claim 16 (depends on 14) The signal analysis circuit of claim 14, wherein said first predefined maximal time interval depends on a number of threshold transition times within said predetermined time period. ### Claim 17 (depends on 12) The signal analysis circuit of claim 12, wherein said set of predefined conditions comprises a second condition, according to which a time interval between a first threshold transition time and a last threshold transition time belonging to the same symbol transition is equal to or less than a second predefined maximum time interval. ### Claim 18 (depends on 17) The signal analysis circuit of claim 17, wherein said second predefined maximum time interval is equal to one of one symbol period and (N−2)/(N−1) symbol periods, where N is an integer equal to or greater than 3. ### Claim 19 (depends on 12) The signal analysis circuit of claim 12, wherein said set of predefined conditions comprises a third condition, according to which an amplitude of said input signal is monotonous over time intervals belonging to the same symbol transition. ### Claim 20 (depends on 12) The signal analysis circuit of claim 12, further comprising a symbol evaluation circuit, said symbol evaluation circuit being configured to determine at least one of a symbol value and a symbol transition time based on said threshold transition times and said amplitude thresholds associated with said threshold transition times.