# US 9,520,910 B1 · Receiver component and method for enhancing a detection range of a time-tracking process in a receiver > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,910 B1 - Document ID: US9520910B1 - Status: Granted - Kind: B1 - Application number: 14/863,572 - Filed: 2015-09-24 - Granted: 2016-12-13 - Earliest claimed: 2015-09-24 - Assignees: NXP B.V. - Applicants: NXP B.V. - Inventors: Sebastian Eckert; Martin Kessel - Web page: https://patentgrep.com/patent/US9520910B1 ## CPC - H04B 1/16: Circuits - H04L 25/0212: {of impulse response} - H04L 27/2663: {Coarse synchronisation, e.g. by correlation} - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L 27/2671: {Time domain} - H04L 27/2675: {Pilot or known symbols} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A receiver component and a method for enhancing a detection range of a time synchronization process in a receiver utilize multiple cross-correlations of a received signal with a known preamble sequence. The results of the multiple cross-correlations are divided into delay segments. The delay segments of one of the multiple cross-correlations are compared with the delay segments of another of the multiple cross-correlations to determine delay of the delay segments of the one of the multiple cross-correlation results. ## Claims ### Claim 1 A method for enhancing a detection range of a time-tracking process in a receiver, the method comprising: performing multiple cross-correlations on different portions of a received signal with a known preamble sequence to derive multiple cross-correlation results; dividing each of the cross-correlation results into a plurality of delay segments; and comparing the delay segments of one of the multiple cross-correlation results with the delay segments of another of the multiple cross-correlation results to determine delay of the delay segments of the one of the multiple cross-correlation results. ### Claim 2 (depends on 1) The method of claim 1, wherein comparing the delay segments of one of the multiple cross-correlation results with the delay segments of another of the multiple cross-correlation results includes comparing magnitudes of the delay segments of one of the multiple cross-correlation results with magnitudes of the delay segments of another of the multiple cross-correlation results to determine delay of the delay segments of the one of the multiple cross-correlation results. ### Claim 3 (depends on 1) The method of claim 1, wherein performing the multiple cross-correlations includes performing a first cross-correlation on a first portion of the received signal with the known preamble sequence and performing a second cross-correlation on a second portion of the received signal with the known preamble sequence, the second cross-correlation being performed at a later time than the first cross-correlation. ### Claim 4 (depends on 3) The method of claim 3, wherein a time difference between performing the first cross-correlation and performing the second cross-correlation is set to half of fast Fourier Transform size used by the receiver. ### Claim 5 (depends on 1) The method of claim 1, wherein dividing each of the cross-correlation results into a plurality of delay segments includes dividing each of the cross-correlation results into four delay segments. ### Claim 6 (depends on 5) The method of claim 5, wherein the length of each of the delay segment is set to quarter of fast Fourier Transform size used by the receiver. ### Claim 7 (depends on 1) The method of claim 1, wherein the known preamble sequence includes Time-Frequency-Phase-Reference (TFPR) symbol. ### Claim 8 (depends on 1) The method of claim 1, wherein the received signal is an orthogonal frequency-division multiplexing (OFDM) based signal. ### Claim 9 A component of a receiver comprising: a plurality of cross-correlation modules configured to perform multiple cross-correlations on different portions of a received signal with a known preamble sequence to derive multiple cross-correlation results; a plurality of division modules coupled to the plurality of cross-correlation modules, the division modules being configured to divide each of the cross-correlation results into a plurality of delay segments; and an ambiguity resolution module configured to compare the delay segments of one of the multiple cross-correlation results with the delay segments of another of the multiple cross-correlation results to determine delay of the delay segments of the one of the multiple cross-correlation results. ### Claim 10 (depends on 9) The component of claim 9, wherein the ambiguity resolution module is configured to compare magnitudes of the delay segments of one of the multiple cross-correlation results with magnitudes of the delay segments of another of the multiple cross-correlation results to determine delay of the delay segments of the one of the multiple cross-correlation results. ### Claim 11 (depends on 9) The component of claim 9, wherein the plurality of cross-correlation modules are configured to perform a first cross-correlation on a first portion of the received signal with the known preamble sequence and to perform a second cross-correlation on a second portion of the received signal with the known preamble sequence, the second cross-correlation being performed at a later time than the first cross-correlation. ### Claim 12 (depends on 11) The component of claim 11, wherein a time difference between performing the first cross-correlation and performing the second cross-correlation is set to half of fast Fourier Transform size used by the receiver. ### Claim 13 (depends on 9) The component of claim 9, wherein the plurality of division modules is configured to divide each of the cross-correlation results into four delay segments. ### Claim 14 (depends on 13) The component of claim 13, wherein the length of each of the delay segment is set to quarter of fast Fourier Transform size used by the receiver. ### Claim 15 (depends on 9) The component of claim 9, wherein the known preamble sequence includes Time-Frequency-Phase-Reference (TFPR) symbol. ### Claim 16 (depends on 9) The component of claim 9, wherein the received signal is an orthogonal frequency-division multiplexing (OFDM) based signal. ### Claim 17 A method for enhancing a detection range of a time-tracking process in a digital audio broadcasting based receiver, the method comprising: performing first and second cross-correlations on a received signal with a known preamble sequence to derive first and second cross-correlation results, wherein the second cross-correlation is time-shifted with respect to the first cross-correlation; dividing each of the first and second cross-correlation results into a plurality of delay segments; and comparing magnitude of the delay segments of the first cross-correlation results with magnitude of the delay segments of the second cross-correlation results to determine delay of the delay segments of the first cross-correlation results. ### Claim 18 (depends on 17) The method of claim 17, wherein a time difference between performing the first cross-correlation and performing the second cross-correlation is set to half of fast Fourier Transform size used by the receiver. ### Claim 19 (depends on 17) The method of claim 17, wherein dividing each of the first and second cross-correlation results into a plurality of delay segments includes dividing each of the first and second cross-correlation results into four delay segments. ### Claim 20 (depends on 17) The method of claim 17, wherein the known preamble sequence includes Time-Frequency-Phase-Reference (TFPR) symbol.