# US 12,015,441 B2 · Pulse-matched filter-based packet detection apparatus and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,441 B2 - Document ID: US12015441B2 - Status: Granted - Kind: B2 - Application number: 17/900,403 - Filed: 2022-08-31 - Published: 2023-05-18 - Granted: 2024-06-18 - Earliest claimed: 2021-11-18 - Assignees: Electronics and Telecommunications Research Institute; Global Lifi Partners Korea Co., Ltd. - Applicants: Electronics and Telecommunications Research Institute; Global Lifi Partners Korea Co., Ltd. - Inventors: Jin Doo Jeong; Sang-Kyu Lim - Web page: https://patentgrep.com/patent/US12015441B2 ## CPC - H04B 10/116: Visible light communication - H04B 1/707: using direct sequence modulation - H04B 10/11: Arrangements specific to free-space transmission, i.e. transmission through air or vacuum - H04L 27/2613: {Structure of the reference signals} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Provided are a pulse-matched filter-based packet detection apparatus and method. The packet detection apparatus includes a photoelectric converter for converting an optical wireless communication signal into an electrical signal, an analog-to-digital converter (ADC) for converting the electrical signal into a digital signal, a pulse-matched filter for outputting a first correlation representing a correlation between a pulse obtained by oversampling a modulated pulse and the digital signal, a correlator for outputting a second correlation representing a correlation between the first correlation and a preamble code, a packet detection signal generator for generating a packet detection signal by comparing the second correlation and a packet detection threshold value, and a demodulator for demodulating the digital signal based on the packet detection signal. ## Claims ### Claim 1 A packet detection apparatus comprising: a photoelectric converter converting an optical wireless communication signal into an electrical signal; an analog-to-digital converter (ADC) converting the electrical signal into a digital signal; a demodulator demodulating the digital signal based on a packet detection signal; and at least one digital signal processor and memory including instructions that, when executed by the at least one digital signal processor, implement: a pulse-matched filter generating and outputting a first correlation representing a correlation between a pulse obtained by oversampling a modulated pulse and the digital signal, the at least one digital signal processor performing the oversampling; a correlator generating and outputting a second correlation representing a correlation between the first correlation and a preamble code stored in the memory; and a packet detection signal generator generating and outputting the packet detection signal by comparing the second correlation and a packet detection threshold value, wherein the optical wireless communication signal is modulated by an on-off keying (OOK) method, and wherein the modulated pulse is used in the on-off keying (OOK) modulation method. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the pulse-matched filter operates by an oversampling clock. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the preamble code is a combination of a Barker code and an inverted Barker code. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the pulse-matched filter is controlled based on a packet demodulation completion signal output by the packet detection signal and the demodulator. ### Claim 5 (depends on 3) The apparatus of claim 3, wherein the pulse-matched filter is inactivated by the pulse detection signal. ### Claim 6 (depends on 3) The apparatus of claim 3, wherein the pulse-matched filter is activated by the packet demodulation completion signal. ### Claim 7 A packet detection method comprising: converting an optical wireless communication signal into an electrical signal; converting the electrical signal into a digital signal; demodulating the digital signal based on a packet detection signal; executing, by at least one digital signal processor, instructions stored in a memory to obtain a first correlation representing a correlation between a pulse obtained by oversampling a modulated pulse and the digital signal; executing, by the at least one digital signal processor, instructions stored in the memory to obtain a second correlation representing a correlation between the first correlation and a preamble code stored in the memory; and executing, by the at least one digital signal processor, instructions stored in the memory to generate the packet detection signal by comparing the second correlation and a packet detection threshold value, wherein the optical wireless communication signal is modulated by an on-off keying (OOK) method, and the modulated pulse is an OOK modulated pulse. ### Claim 8 (depends on 7) The method of claim 7, wherein the first correlation is obtained from a pulse-matched filter operating by an oversampling clock. ### Claim 9 (depends on 7) The method of claim 7, wherein the preamble code is a combination of a Barker code and an inverted Barker code. ### Claim 10 (depends on 8) The method of claim 8, wherein the pulse-matched filter is controlled based on a packet demodulation completion signal output after the packet detection signal and the digital signal are demodulated. ### Claim 11 (depends on 10) The method of claim 10, wherein the pulse-matched filter is inactivated by the packet detection signal. ### Claim 12 (depends on 10) The method of claim 10, wherein the pulse-matched filter is activated by the packet demodulation completion signal. ### Claim 13 An optical wireless communication device comprising: a light receiving module receiving an optical signal; and a packet detection apparatus detecting an optical wireless communication signal among the received optical signals, wherein the packet detection apparatus comprises: a photoelectric converter converting the optical wireless communication signal into an electrical signal; an analog-to-digital converter (ADC) converting the electrical signal into a digital signal; a demodulator configured to demodulate the digital signal based on a packet detection signal; and at least one digital signal processor and memory including instructions that, when executed by the at least one digital signal processor, implement: a pulse-matched filter generating and outputting a first correlation representing a correlation between a pulse obtained by oversampling a modulated pulse and the digital signal, the at least one digital signal processor performing the oversampling; a correlator generating and outputting a second correlation representing a correlation between the first correlation and a preamble code stored in the memory; and a packet detection signal generator generating and outputting the packet detection signal by comparing the second correlation and a packet detection threshold value, wherein the optical wireless communication signal is modulated by an on-off keying (OOK) method, and wherein the modulated pulse is used in the on-off keying (OOK) modulation method.