# US 10,502,827 B2 · Addressing inter-node phase noise in non-coherent radar system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,827 B2 - Document ID: US10502827B2 - Status: Granted - Kind: B2 - Application number: 15/976,200 - Filed: 2018-05-10 - Published: 2019-11-14 - Granted: 2019-12-10 - Earliest claimed: 2018-05-10 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Oded Bialer; Amnon Jonas - Web page: https://patentgrep.com/patent/US10502827B2 ## CPC - G01S 13/931: of land vehicles - H04B 10/66: Non-coherent receivers, e.g. using direct detection - G01S 7/4021: {of receivers} - G01S 13/003: {Bistatic radar systems; Multistatic radar systems} - G01S 13/36: with phase comparison between the received signal and the contemporaneously transmitted signal - G01S 13/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S13/46) - H04B 10/6165: {Estimation of the phase of the received optical signal, phase error estimation or phase error correction} - G01S 2013/9325: {for inter-vehicle distance regulation, e.g. navigating in platoons} - G01S 2013/93271: {in the front of the vehicles} - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - H04B: TRANSMISSION ## Abstract A radar system and method of detecting an object involve a first node including a first transmitter and a first receiver, and a second node including a second transmitter and a second receiver. The second receiver receives a first received signal from an object from a first transmission by the first transmitter, the first received signal including first phase noise with a first delay, and the first receiver receives a second received signal from the object from a second transmission by the second transmitter, the second received signal including second phase noise with a second delay. A processor processes the first transmission, the first received signal, the second transmission, and the second received signal to eliminate the inter-node phase noise and to estimate a location of the object relative to the radar system based on the first delay and the second delay. ## Claims ### Claim 1 A radar system, comprising: a first node including a first transmitter and a first receiver; a second node, spaced apart from the first node, including a second transmitter and a second receiver, wherein the second receiver receives a first received signal from an object resulting from reflection of a first transmission by the first transmitter, the first received signal including first phase noise, which is associated with the first transmitter, with a first delay, and the first receiver receives a second received signal from the object resulting from reflection of a second transmission by the second transmitter, the second received signal including second phase noise, which is associated with the second transmitter, with a second delay; and a processor configured to address inter-node phase noise represented by the first phase noise and the second phase noise by processing the first transmission, the first received signal, the second transmission, and the second received signal to eliminate the inter-node phase noise and to estimate a location of the object relative to the radar system based on the first delay and the second delay. ### Claim 2 (depends on 1) The system according to claim 1, wherein the processor is further configured to obtain a first result as a conjugate multiplication of the first received signal and the first transmission and to obtain a second result as a conjugate multiplication of the second received signal and the second transmission. ### Claim 3 (depends on 2) The system according to claim 2, wherein the processor is further configured to obtain an inter-node signal between the first node and the second node by multiplying the first result and the second result to obtain a periodic signal with a frequency that is a sum of the first delay and the second delay. ### Claim 4 (depends on 3) The system according to claim 3, wherein the periodic signal is a sinusoid. ### Claim 5 (depends on 3) The system according to claim 3, further comprising two or more additional nodes, wherein the processor is further configured to obtain the inter-node signal between every pair of the nodes in the system. ### Claim 6 (depends on 1) The system according to claim 1, wherein the processor estimates the location of the object based additionally on intra-node signals that include a first intra-node received signal received at the first receiver based on the reflection of the first transmission and a second intra-node received signal received at the second receiver based on the reflection of the second transmission. ### Claim 7 (depends on 1) The system according to claim 1, wherein the system is part of a vehicle and the estimate of the location of the object is used to augment or automate vehicle operation. ### Claim 8 (depends on 7) The system according to claim 7, wherein the first node and the second node have overlapping fields of view. ### Claim 9 A method of detecting an object with a radar system that includes a first node with a first transmitter and a first receiver and a second node with a second transmitter and a second receiver, the method comprising: the second receiver receiving a first received signal from the object resulting from reflection a first transmission by the first transmitter, the first received signal including first phase noise, which is associated with the first transmitter, with a first delay; the first receiver receiving a second received signal from the object resulting from reflection of a second transmission by the second transmitter, the second received signal including second phase noise, which is associated with the second transmitter, with a second delay; and estimating, using a processor, a location of the object relative to the radar system based on the first delay and the second delay by processing the first transmission, the first received signal, the second transmission, and the second received signal to eliminate inter-node phase noise represented by the first phase noise and the second phase noise. ### Claim 10 (depends on 9) The method according to claim 9, further comprising obtaining a first result as a conjugate multiplication of the first received signal and the first transmission and a second result as a conjugate multiplication of the second received signal and the second transmission. ### Claim 11 (depends on 10) The method according to claim 10, further comprising obtaining an inter-node signal between the first node and the second node by multiplying the first result and the second result to obtain a periodic signal with a frequency that is a sum of the first delay and the second delay. ### Claim 12 (depends on 11) The method according to claim 11, wherein obtaining the periodic signal includes obtaining a sinusoid. ### Claim 13 (depends on 9) The method according to claim 9, wherein the estimating the location of the object is based additionally on intra-node signals that include a first intra-node received signal received at the first receiver based on the reflection of the first transmission and a second intra-node received signal received at the second receiver based on the reflection of the second transmission. ### Claim 14 A vehicle, comprising: radar system, comprising: a first node including a first transmitter and a first receiver; a second node, spaced apart from the first node, including a second transmitter and a second receiver, wherein the second receiver receives a first received signal from an object resulting from reflection of a first transmission by the first transmitter, the first received signal including first phase noise, which is associated with the first transmitter, with a first delay, and the first receiver receives a second received signal from the object resulting from reflection of a second transmission by the second transmitter, the second received signal including second phase noise, which is associated with the second transmitter, with a second delay; and a processor configured to address inter-node phase noise represented by the first phase noise and the second phase noise by processing the first transmission, the first received signal, the second transmission, and the second received signal to eliminate the inter-node phase noise and to estimate a location of the object relative to the radar system based on the first delay and the second delay; and a vehicle controller configured to augment or automate vehicle operation based on the location of the object. ### Claim 15 (depends on 14) The vehicle according to claim 14, wherein the processor is further configured to obtain a first result as a conjugate multiplication of the first received signal and the first transmission and to obtain a second result as a conjugate multiplication of the second received signal and the second transmission. ### Claim 16 (depends on 15) The vehicle according to claim 15, wherein the processor is further configured to obtain an inter-node signal between the first node and the second node by multiplying the first result and the second result to obtain a periodic signal with a frequency that is a sum of the first delay and the second delay. ### Claim 17 (depends on 16) The vehicle according to claim 16, wherein the periodic signal is a sinusoid. ### Claim 18 (depends on 16) The vehicle according to claim 16, further comprising two or more additional nodes, wherein the processor is further configured to obtain the inter-node signal between every pair of the nodes in the system. ### Claim 19 (depends on 14) The vehicle according to claim 14, wherein the processor estimates the location of the object based additionally on intra-node signals that include a first intra-node received signal received at the first receiver based on the reflection of the first transmission and a second intra-node received signal received at the second receiver based on the reflection of the second transmission.