SE2251059A1 - An fmcw radar system with increased capacity - Google Patents
An fmcw radar system with increased capacityInfo
- Publication number
- SE2251059A1 SE2251059A1 SE2251059A SE2251059A SE2251059A1 SE 2251059 A1 SE2251059 A1 SE 2251059A1 SE 2251059 A SE2251059 A SE 2251059A SE 2251059 A SE2251059 A SE 2251059A SE 2251059 A1 SE2251059 A1 SE 2251059A1
- Authority
- SE
- Sweden
- Prior art keywords
- ego
- frequency
- radar
- time
- vehicle
- Prior art date
Links
- SJQBHPJLLIJASD-UHFFFAOYSA-N 3,3',4',5-tetrachlorosalicylanilide Chemical compound OC1=C(Cl)C=C(Cl)C=C1C(=O)NC1=CC=C(Cl)C(Cl)=C1 SJQBHPJLLIJASD-UHFFFAOYSA-N 0.000 claims abstract description 11
- 238000000034 method Methods 0.000 claims description 24
- 230000001360 synchronised effect Effects 0.000 claims description 8
- 238000004891 communication Methods 0.000 description 11
- 230000005540 biological transmission Effects 0.000 description 9
- 238000012545 processing Methods 0.000 description 8
- 230000002452 interceptive effect Effects 0.000 description 7
- 230000008901 benefit Effects 0.000 description 3
- 238000004590 computer program Methods 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 101100048480 Vaccinia virus (strain Western Reserve) UNG gene Proteins 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000002085 persistent effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/023—Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/023—Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques
- G01S7/0235—Avoidance by time multiplex
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/06—Systems determining position data of a target
- G01S13/08—Systems for measuring distance only
- G01S13/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
- G01S13/34—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
- G01S13/345—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal using triangular modulation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/93—Radar or analogous systems specially adapted for specific applications for anti-collision purposes
- G01S13/931—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of land vehicles
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/023—Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques
- G01S7/0232—Avoidance by frequency multiplex
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/06—Systems determining position data of a target
- G01S13/08—Systems for measuring distance only
- G01S13/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/93—Radar or analogous systems specially adapted for specific applications for anti-collision purposes
- G01S13/931—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of land vehicles
- G01S2013/9316—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of land vehicles combined with communication equipment with other vehicles or with base stations
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/003—Transmission of data between radar, sonar or lidar systems and remote stations
Abstract
The present disclosure relates to a vehicle radar system (210; 210A, 210B, 210C) comprising a control unit (208) and at least one radar transceiver arrangement (201, 202, 203, 204, 205) arranged to generate and transmit an FMCW signal (220) in a radar frequency band. Each FMCW signal (220) comprises a corresponding plurality of ego frequency ramps (r; ra, rb, rc, rd, re) that are generated in radar cycles having a certain ego cycle time (tc) and ego cycle start time (tcs; tcsa, tcsb, tcsc, tcsd, tcse) , where each one of the ego frequency ramps (r; ra, rb, rc, rd, re) has a certain ego duration time (tr) , an ego delay time (tD) between adjacent ego frequency ramps (r) and an ego frequency gradient (df/dt). The control unit (208) is adapted to receive synchronization information from at least one external unit (400, 420, 430, 450; 208A, 208B, 208C; 460), and to base at least the ego cycle start time (tcs; tcsa, tcsb, tcsc, tcsd, tcse) , the ego duration time (tr) and the ego delay time (tD) on the synchronization information.(Fig. 5)
Description
TITLE AN FMCW RADAR SYSTEM WITH INCREASED CAPACITY
DESCRIPTION OF THE DISCLOSURE The present disclosure relates to radar systems adapted
for automotive applications. There are disclosed radar
systems and methods for operating radar systems.
A radar transceiver is, normally, a device arranged for
transmission and reception of radar signals in a dedicated radar frequency band. Radar transceivers are commonly used in vehicles for monitoring vehicle surroundings. Automatic
Cruise Control (ACC) functions, Emergency Braking (EB)
functions, Advanced Driver Assistance Systems (ADAS) and
Autonomous Drive (AD) are some examples of applications
where radar data represents an important source of
information on which vehicle control is based.
Many of the dedicated automotive radar frequency bands
allow uncoordinated transmission, which means that two or
more radar transceivers may transmit at the same time in
the same frequency band, and thus interfere with each
other.
EP 3244229 discussed the general effects of interference
on a frequency' modulated. continuous wave (FMCW) radar
system, and proposed methods to repair an interfered radar signal. Despite the often impressive efficiency' of previously
proposed. repair methods, there is a need for further
improvements in vehicular radar systems in order to reduce
interference, and possibly to provide a lower cost means
of avoiding interference for radar transceivers.
SUMMARY
It is an object of the present disclosure to provide
improved vehicle radar systems where interference is
reduced or removed entirely, compared to known vehicular
radar systems, such as uncoordinated automotive radar based on uncoordinated FMCW transmission.
This object is obtained by a vehicle radar system comprising a control unit and at least one radar
transceiver arrangement arranged to generate and transmit an FMCW, Frequency Modulated Continuous Wave, signal in a radar frequency band and to receive reflected signals that have been reflected by one or more target objects. Each FMCW signal comprises a corresponding plurality of ego frequency ramps that are generated in radar cycles having a certain ego cycle time and ego cycle start time. Each one of the ego frequency ramps has a certain ego duration time, an ego delay time between adjacent ego frequency ramps and an ego frequency. The control unit is adapted to receive information from. at least
synchronization one
external unit, and to base at least the ego cycle start time, the ego duration time and the ego delay time on the synchronization information.
In this way, the vehicle radar system may adapt the ego cycle start time, the ego duration time and the ego delay time such that interference is minimized, while enabling frequency ramps from other radar systems to be interleaved
in a non-interfering manner.
According to some aspects, the ego frequency gradient df/dt
is based on the synchronization information.
This means that all radar transceivers adopt to a common frequency gradient or slope of their FMCW transmissions. When this common frequency gradient is used by other radar systems in other vehicles, it is possible to avoid that the frequency ramps cross but can run in an interleaved non-interfering manner. According to some aspects, the synchronization information comprises time reference data, where the control unit is adapted to control the ego cycle start time in dependence of the time reference data.
By using an externally derived timing reference, all radar systems within an area can maintain the same slope gradient as well as fixed starting frequencies. By defining a set of fixed starting times, for example at 2us intervals one
can define a set of “timeslots”. The timeslots would be
defined by their start time and starting frequency. The periodicity would be fixed, for example at 64us such that a block of chirps all occupying the same timeslot could be sent and in such an example there would be 32 timeslots to choose from. Different radar transceivers around the vehicle and in neighbouring vehicles can select a timeslot to avoid interference. An external observer would see all radar transceivers operating at the same time and in the
same band, in an interleaved pattern.
According to some aspects, the synchronization information
comprises a frequency reference, where the control unit is
adapted to control at least one radar transceiver arrangement to generate ego frequency ramps in dependence
of the frequency reference.
The use of external frequency reference would ensure that
the chirp or frequency ramp gradient is maintained precisely as if the gradient or timing is slightly wrong then over the course of multiple chirps two chirp signals may become too close together and cause interference.
According to some aspects, the synchronization information comprises information regarding at which times neighboring radar transceivers are transmitting neighboring frequency ramps and with which neighboring frequency gradient. The
control unit is adapted. to control the ego frequency gradient to correspond to the synchronization information and to schedule the ego frequency ramps in free timeslots
between the neighboring frequency ramps.
This further adds to enabling the frequency ramps to run in an interleaved non-interfering manner.
According to some aspects, the control unit is adapted to control at least one radar transceiver arrangement to monitor a certain part of the radar frequency band during an observation period, to analyze possible interference signals. The control unit is further adapted to identify a certain start time to start sending a cycle of one or
more ego frequency ramps in dependence of said analysis,
such that interference from said interference signals is
reduced.
The radar frequency band can thus be monitored to determine
which timeslots that are occupied and which are free. The
control unit may then control the radar transceiver
arrangements to transmit on that timeslot for one or more
radar cycles, periodically checking that the timeslot is
still free.
According to some aspects, each radar transceiver
arrangement is associated with a main pointing direction
and a pre-defined set of timeslots O..N, where each
timeslot TS@_Ncorresponds to a sequence of ego frequency ramps within a frame and the timeslot number corresponds
to a time offset.
The control unit is adapted to define heading intervals
which divide a full turn interval O°- 360° into sections,
and to assign a corresponding timeslot to each heading
interval. The control unit is further adapted to determine
a present vehicle heading, and to assign a corresponding
timeslot to each one of the radar transceivers in
dependence of the heading' interval that comprises the
present vehicle heading.
This way, those radar transceivers that are most likely to
interfere or attract interference are controlled to
generate interleaved frequency ramps.
According to some aspects, the radar transceiver
arrangements are adapted to transmit a stepped FMCW waveform whereby the radar transceiver arrangements are synchronised. such. that the corresponding' ego frequency
ramps are aligned to occupy one timeslot each.
This means that the present disclosure is applicable for
stepped frequency ramps as well.
Some vehicle radar systems may use a stepped FMCW radar waveform that only occupy a part of the lGHz band for any
one frequency ramp. In such stepped FMCW systems, multiple
radar radar transceivers around the vehicle may be
transmitting at the same time,
the band.
but in different parts of
According to some aspects, all stepped FMCW radar
transceivers around the vehicle are synchronised in time and frequency such that the radar chirps appear as a near single continuous chirp and hence still occupy a small
number of timeslots. This allows regular FMCW and stepped
FMCW radar radar transceivers to avoid interference with
each other.
There are also disclosed herein vehicles and methods
associated with the above-mentioned advantages.
Generally, all terms used in the claims are to be
interpreted according to their ordinary meaning in the
technical field, unless explicitly defined otherwise
herein. All references to "a/an/the element, apparatus,
component, means, step, etc." are to be interpreted openly
as referring to at least one instance of the element,
apparatus, component, means, step, etc., unless explicitly
stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.
Further features of, and. advantages with, the present disclosure will become apparent when studying the appended claims and the following description. The skilled person realizes that different features of the present disclosure may be combined to create embodiments other than those described in the following, without departing from the
scope of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure will now be described in more detail
with reference to the appended drawings, where
Figure l schematically illustrates a prior art traffic scenario;
Figure 2 schematically shows a top view of a vehicle;
Figure 3 schematically shows a top view of a vehicle with heading intervals;
Figure 4 schematically shows frequency ramps of an FMCW signal;
Figure 5 schematically shows ego frequency ramps with
interleaved neighbor frequency ramps;
Figure 6 schematically shows a detail of Figure 5;
Figure 7 schematically shows stepped FMCW signals transmitted multiple radar trasnsceiver arrangementss in a vehicle;
Figure 8 schematically shows a less detailed view of Figure 7;
Figure 9 schematically illustrates a traffic scenario according to the present disclosure;
Figure 10 schematically illustrates a vehicle radar system;
Figure 11 schematically illustrates a control unit;
Figure 12 shows an example computer program product; and
Figure 13 is a flow chart illustrating methods.
DETAILED DESCRIPTION
Aspects of the present disclosure will now be described more fully with reference to the accompanying drawings. The different devices and methods disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth
herein. Like numbers in the drawings refer to like elements
throughout.
The terminology used herein is for describing aspects of
the disclosure only' and. is not intended. to limit the
disclosure. As used herein, the singular forms "a" "an"
and "the" are intended to include the plural forms as well,
unless the context clearly indicates otherwise.
Figure 1 shows a prior art traffic scenario 100 where vehicles 110, 120, 130, 140 travel on a road 101. Each vehicle comprises one or more radar transceivers that
transmit in a common frequency band in an uncoordinated
manner, which means that radar transceivers may
unknowingly interfere with each other.
In Figure 1, the front radar transceivers of vehicle 120 and vehicle 130 may generate interfere to each other, as well as the front radar transceivers of vehicle 110 and
vehicle 140. Vehicle 120 also comprises rearward looking
corner radar transceivers which may interfere with, e.g., the front radar transceiver of vehicle 110. As shown in Figure 2, there is an ego vehicle 200, having
a present vehicle heading F, that comprises a vehicle radar
system 210 that, as also shown in Figure 10, i11 turn
and at least radar
203, 204,
a control unit 208
202,
comprises one
transceiver arrangement 201, 205 arranged to generate and. transmit an FMCW, Frequency' Modulated Continuous Wave, signal 220 in a radar frequency band and to receive reflected signals 221 that have been reflected by one or more target objects 222.
a first front
Here, there is a front radar transceiver 201,
corner radar transceiver 202, a second front corner radar transceiver 203, a first rear corner radar transceiver
204, a second rear corner radar transceiver 205 and a
control unit 208.
204,
Each corner radar transceiver 202, 203, 205 is associated with a corresponding coverage main or boresight direction P1, P2, P3, P4 around which mutually different radar coverages are obtained in a known manner using FMCW chirp signals of frequency ramps.
With reference to Figure 4, each FMCW signal 220 is in the form of a continuous sinusoid where the frequency varies from
a first frequency fsæït to a second frequency fswp
over the course of an ego frequency ramp r, where the
magnitude of the first frequency' faan; falls below the magnitude of the second frequency füqw Each FMCW signal 220 thus comprises a corresponding plurality of ego frequency ramps r that are generated in radar cycles having a certain ego cycle time tc and ego cycle start time tcp Each one of the ego frequency ramps r has a certain ego duration time tr, ego delay time tD between adjacent ego frequency ramps r and an ego frequency gradient df/dt.
According to the present disclosure, the control unit 208 is adapted to receive synchronization information from at least one external unit, and to base at least the ego cycle start time tæ, the ego duration time tr and the ego delay time tD on the synchronization information.
In this an external unit
context, is not part of the
vehicle radar system 210, and is in practice positioned at a certain distance from the vehicle radar system 210. When the vehicle radar system 210 is positioned in a vehicle
200, that external unit is not part of the vehicle 200.
ll
An external unit is according to some aspects constituted
by' an external radio transmitting' device, or at least
comprises an external radio transmitting device.
In this way, the vehicle radar system 2l0 may adapt the
ego cycle start time tæ, the ego duration time tr and the
ego delay time tD such that interference is ndnimized,
while enabling frequency ramps from other radar systems
2l0A, 2l0B, 2l0C, 2l0D to be interleaved with the ego
frequency ramps r in a non-interfering manner.
According to some aspects, the ego frequency gradient df/dt
is based on the synchronization information.
This means that all radar transceivers adopt to a common
frequency gradient or slope df/dt of their FMCW
transmissions. When this common frequency gradient df/dt is used by other radar systems in other vehicles 200A, 200B, 200C, 200D, it is possible to avoid that the frequency ramps cross but can run in an interleaved non- interfering manner.
According to some aspects, with reference also to Figure 9, external units may include a communication system 400. This may,
e.g., be a third generation partnership program
(BGPP) defined access network like the fourth generation (4G) or the fifth generation (5G) access networks or a satellite system. such as GPS. The access network may
provide access to remote networks and other resources such
as, e.g., the Internet.
l2
It is also appreciated that some processing functions may be performed by resources in a remote network 420, such as
a remote server 430.
External units may also include one or more satellites 450 208B, 208C 208D that are
200C, 200D, in
and neighbor control units 208A, positioned in neighbor vehicles 200A, 200B, the latter case the communication is in the form of V2V
(vehicle to vehicle) communication 462. Such V2V
communication 462 could comprise information about radar transceiver timing characteristics as well as information remote
forwarded from any other external unit such as
servers 430 and satellites 430. In addition, external units may also include fixed infrastructure items such as traffic lights 460, where the communication is
road signs, etc.,
in the form of V2X communication
46l.
(vehicle to anything) Such communication 462 could comprise environmental information as well as information forwarded from any other satellites 430 2l0D.
external unit such as remote servers 430, and neighbor radar systems 2l0A, 2l0B, 2l0C, With reference to Figure 5 and Figure 6 that shows a detail
of Figure 5, the radar transceivers 20l, 202, 203, 204, 205 are adapted to operate using defined timeslots TSW TSb.
In Figure 5, the front radar transceiver 201 transmits a first series of frequency ramps r¿ with a first cycle start time tæa (only two ramps shown, marked with solid lines), the first front corner radar transceiver 202 transmits a second series of frequency ramps rb with a second cycle marked with a short
start time tæb (only one ramp shown,
l3
dashed line), the second front corner radar transceiver
203 transmits a third series of frequency ramps rd with a marked
third cycle start time tæd (only one ramp shown,
with a dashed-dotted line), the first rear corner radar transceiver 204 transmits a fourth series of frequency ramps rd with a fourth cycle start time tæd (only one ramp
shown, marked with a long dashed line), and the second
rear corner radar transceiver 205 transmits a fifth series of frequency ramps rd with a fifth cycle start time tdæ (only one ramp shown, marked with a dashed double-dotted
line).
The frequency ramps rd, rb, rd, rd, rd, continue during
their* cycle times as indicated. with. dashed. lines, all
having a common frequency gradient, or slope, df/dt. Each
frequency ramp rd, rb, rd, rd, rdoccupies a corresponding timeslot TSd, TSb as illustrated for the first series of frequency ramps rd and the second series of frequency ramps
rb in Figure 6.
Figure 5 and Figure 6 illustrates the timeslot structure according to the present disclosure where each timeslot corresponds to the usage of the entire bandwidth using a defined frequency gradient df/dt and cycle start time tæ; taga, taga, taga
tcsa/ tcsb/
Offsetting the timeslots TSd, TSb in time allows different FMCW radar trasncivers to be interleaved and still ensuring sufficient spacing between the frequency ramp. This is
illustrated in Figure 5, Figure 6 and Figure 9.
l4
In Figure 9, the ego vehicle 200 is travelling in a traffic situation together with a first neighbor vehicle 200A, second neighbor vehicle 200B, third neighbor vehicle 200C and fourth neighbor vehicle 200D.
Each neighbor vehicle 200A, 200B, 200C, 208B, 20lC,
202B,
200D comprises a 208C, 208D, 20lD, 202C, 203B,
corresponding control unit 208A, front
20lB, first front 202D,
203C,
radar transceiver 20lA, second
203D,
corner radar transceiver 202A, front corner radar transceiver 203A, first rear corner radar transceiver 204A, 204B, 204C, 204D,
and second rear corner radar transceiver 205A, 205B, 2050,
205D.
In Figure 5 and Figure 6 there is enough space between the
ego timeslots TSa, TSb to accommodate four further
intermediate timeslots TSU, TSQ, TSB, TSM, where these
intermediate timeslots TSih TSi@ TSi@ TSi4 each
accommodates one intermediate frequency ramp ri; rn, rih
rm, 134 each, each intermediate frequency ramp rih ru,
rm, rfl being comprised in a corresponding cycle of
intermediate frequency ramps, each cycle having a
corresponding cycle start time tæih tC¶¿, tcæß, tcæi. Only
a few timeslots are indicated in Figure 6 for reasons of
clarity, but every frequency ramp is occupying a
corresponding timeslot.
The intermediate frequency ramps ri; rn, rih ;m3, rfl can
be transmitted from one or more of the neighboring vehicles 200A, 200B, 200C, 200D. This is enabled since the frequency gradient df/dt is the same for all frequency ramps ra, rb,
rc, rii, re; rii, rig, rig, ri4 and all cycle start times tcsa,
tcsb/ tcsc/ tcsd/ tcse; tcsil/ tcsi2/ tcsi3/ tcsill are SynchrOnj-Zed
accordingly. Furthermore, all frequency ramps ra, rb, rm
rfl, re; rn, rik 133, rfl have a common ramp time and delay
time, such that all frequency ramps r¿, rb, rc, rd, re; rn,
rn, rm, rfl have similar characteristics and can be
transmitted in an interleaved manner without interfering
with each other.
The timeslots allow a sequence of for example 32 chirps,
or frequency ramps, to be sent by different radar
transceiver within a 64us “frame” period. The timeslots
are then repeated in the next frame.
This is all enabled by the control unit 208 being adapted to receive synchronization information from at least one described above,
208A, 208B, 208C,
external unit as and preferably all
control units 208, 208D are adapted to
receive the synchronization information.
According to some aspects, the synchronization information
comprises time reference data, where the control unit 208
is adapted to control the ego cycle start time tm; tcæ,
tæd, tæe in dependence of the time reference
tcsb/ tcsc/
data.
The accurate start time of each slot may according to some
aspects be derived. by a GNSS signal and. this may' be
distributed accurately to radar transceivers around the vehicle, for example using PTP. According to some aspects, the synchronization information
comprises a frequency reference, where the control unit
16
208 is adapted to control at least one radar transceiver
arrangement 201, 202, 203, 204 205 to generate ego
frequency ramps r; ra, rb, rc, rd, re in dependence of the
frequency reference.
The use of external frequency reference would ensure that
the chirp or frequency ramp gradient is maintained
precisely as if the gradient or timing is slightly wrong then over the course of multiple chirps two chirp signals
may become too close together and cause interference.
By using an externally derived timing reference, all radar
systems within an area can maintain the same slope gradient
as well as fixed starting frequencies. By defining a set
of fixed starting times, for example at 2us intervals one
can define a set of “timeslots”. In this context, the
timeslots would be defined by their start time and starting
frequency. The periodicity would be fixed, for example at
64us such that a block of chirps all occupying the same timeslot could be sent and in such an example there would
be 32 timeslots to choose from. Different radar
transceivers around the vehicle and in neighbouring
vehicles can select a timeslot to avoid interference. An
external observer would see all radar transceivers
operating at the same time and in the same band, in an
interleaved pattern.
According to some aspects, the synchronization information
comprises information regarding at which times tcül, tæih
tcæg, tcæl neighboring radar transceivers are transmitting
neighboring frequency ramps ri; rn, rgg, rm, 154 and with
which neighboring frequency gradient df/dt. The control
17
unit 208 is adapted to control the ego frequency gradient df/dt to correspond to the synchronization information and to schedule the ego frequency ramps r; rd, rb, rd, rd, rd in free timeslots between the neighboring frequency ramps
Ii; Iii, Ii2, Ii3, Ii4-
In this way, neighboring frequency ramps rd; rn, ru, riy
rfl can be interleaved with ego frequency ramps r; rd, rb,
rd, rd, rd in a non-interfering manner.
According to some aspects, the control unit 208 is adapted
to control at least one radar transceiver arrangement 201,
202, 203, 204, 205 to monitor a certain part of the radar
frequency band during an observation period, to analyze
possible interference signals ri; rn, rn, rg, rdr and to
identify a certain start time tas; tcsd, tdsb, tddd, tdsd, tddd
to start sending a cycle of one or more ego frequency ramps such
r; rd, rb, rd, rd, rd in dependence of said analysis,
that interference from said interference signals ri; rn,
Iig, Ii3, Ii4 lS IGdUCGd..
For example, the radar system 210 could monitor the first 64us of a cycle in order to select the best timeslot and then start transmission for one or more radar transceivers 201, 202, 203, 204, 205. 202, 203, 204,
Said radar transceiver 201, 205 may for that reason forgo that first chirp of its cycle, or may extend the transmission to obtain a full set of chirps.
According to some aspects, the control unit 208 is adapted
information
208C,
to receive
208A, 208B,
from. neighboring control units
208D regarding neighboring timeslots
18
TSH, TSQ, TSB, TSM, and to determine an ego timeslot
structure with corresponding ego timeslots TSA, TSB; TSM
Tsg, Ts17. The radar frequency band can thus be monitored to determine which timeslots that are occupied and which are free. The
control unit 208 may then control the radar transceiver
arrangements 201, 202, 203, 204, 205 to transmit on that timeslot for one or more radar cycles, periodically checking that the timeslot is still free. Alternatively
timeslots may be changed in a random fashion.
According to some embodiments, the the control unit 208 is
least radar transceiver
204,
control at
202, 203,
adapted to one
arrangement 201, 205 to monitor a random
number of frames before selecting its timeslot within the
Nth frame. Typically, radar transceivers do not transmit
for the whole cycle time of for example 50ms. In fact they
may often only transmit for example 40% of the cycle. Hence
it is never critical that radar transceivers start
transmitting at exactly the same start time. Having
selected a timeslot, the radar would then use that timeslot for the next M cycles starting at the beginning of the frame. This would give other radar transceivers that were monitoring the first 64us to select their timeslot with due warning that the timeslot was already in use.
In other embodiments, the 50ms cycle is divided into two sub-periods each of 25ms. A radar transceiver may only
transmit on one of the two sub-periods. Again, the sub-
periods would derive their timing from an external source.
19
According to some aspects, with reference to Figure 2 and
Figure 3, 202,
203, 204,
each radar transceiver arrangement 201, 205 is associated with a main pointing direction F, P1, P2, P3, P4 and a pre-defined set of timeslots 0..N, where each timeslot TS@_Ncorresponds to a sequence of ego frequency ramps ra, rb, rc, rd, re within a frame and the timeslot number corresponds to a time offset. The control
unit 208 is adapted to:
- define heading intervals 310 which divide a full turn
interval 0°- 360° into sections 310,
- assign a corresponding timeslot to each heading
interval 310,
- determine a present vehicle heading F, and to
- assign a corresponding timeslot to each one of the
radar transceivers 201, 202, 203, 204, 205 in dependence of the heading interval 310 that comprises the present vehicle heading F.
This way, only those radar transceivers that are likely to
interfere are controlled to generate interleaved frequency
ramps.
According to some aspects, the control unit 208 is adapted
to determine a present vehicle heading by means of GNSS
(Global Navigation Satellite System) or magnetic compass
data.
According to some aspects, the control unit is adapted to
determine a present vehicle heading by determining a
predominant road extension direction.
In Figure 3, for reasons of clarity' only' one heading
interval/section 310 is indicated. Normally there is a
plurality (If heading' intervals/sections
360°.
along' the full turn interval 0°- In this way, unwanted toggling is avoided.
Figure 7 illustrates a stepped FMCW signal transmitted by
the radar transceivers 201, 202, 203, 204, 205. A stepped FMCW signal is typically transmitted in shorter chirps, but from chirp to chirp the centre frequency changes in a linear fashion.
In Figure 7, there are stepped frequency ramps where a first stepped frequency ramp is constituted by a first ramp r¿1 from the first series of frequency ramps ra, a first ramp rm from the second series of frequency ramps rb, and a first ramp rd from the third series of frequency ramps rc. In the same manner there is a second stepped
frequency ramp rak nü, r¿2 and a third stepped frequency
ramp ra3/ rb3/ rc3-
Figure 7 is a detail of Figure 8 that illustrates stepped frequency radar cycles Ca, Cb, CC, Cd, CG for all the radar
transceivers 201, 202, 203, 204, 205. A time window At of
Figure 8 is illustrated in Figure 7.
radar
205
the 204,
According to some aspects,
201,
generally,
transceiver arrangements 202, 203, are
adapted to transmit a stepped FMCW waveform whereby the radar transceiver arrangements 201, 202, 203, 204, 205 are
synchronised. such. that the corresponding' ego frequency
2l
ramps ra, rb, rc, rd, re are aligned to occupy one timeslot
TS1, TS9, TS17 each.
In this example, each of the stepped frequency ramps occupy
a corresponding timeslot TS1, TS7, TSU, where there are 8
free timeslots between each stepped frequency ramp. This
means that it is possible to fit eight intermediate stepped frequency ramps between each stepped frequency ramp raw
Ibl, Jfçlr' lfag, Ibg, fç2f' ra3, Ib3, IC3 in thG SäITIG ITIGIIÛGI 8.8
described previously.
This means that the present disclosure is applicable for stepped frequency ramps as well. 202,
In Figure 7 and Figure 8, the radar transceivers 20l,
203, 204, 205 from the same vehicle 200 are accurately time synchronised such that they occupy a minimum number of timeslots, which were defined previously for the FMCW radar. Note that the gradient is still the same and thus a stepped FMCW radar and an FMCW radar could interleave their signals and avoid interference with each other.
even if the radar
still work
203,
could
202,
Interleaving
transceivers 20l, 204, 205 from the same vehicle
200 would not be accurately time synchronised, each stepped frequency ramp would occupy many timeslots thus reducing the number of intermediate stepped frequency ramps that can be interleaved between the stepped frequency ramps ra,
Ibi, Icií Ia2, Ib2, I@2; Ia3, Ib3, IC3-
22
A system of stepped FMCW signals would need to occupy more timeslots than a regular FMCW radar because the chirps,
being shorter, are also closer together.
Some vehicle systems may use a stepped FMCW radar waveform, which only occupies a part of the lGHz band for any one
chirp. In such stepped FMCW systems, multiple radar
transceivers around the vehicle may be transmitting at the
same time, but in different parts of the band.
According to some aspects, all stepped FMCW radar
transceivers around the vehicle are synchronised in time and frequency such that the radar chirps appear as a near single continuous chirp and hence still occupy a small number of timeslots. This allows regular FMCW and stepped FMCW radar transceivers to avoid interference with each other.
According to some aspects, the slope of the timeslots TSM TS9, TSU is positive in some stepped frequency radar cycles Ca-CG and negative in some stepped frequency radar cycles C'a-C'e.
In other words, Figure 8 also highlights a potential problem created by stepped FMCW radar transceivers which is that in some implementations their stepping direction is not always positive. It may be necessary to impose only
a positive stepping direction. Alternatively, the
timeslots could be devised such that in even cycle numbers
O, 2, 4, etc the timeslot represents a positive gradient
and in odd timeslots number l, 3, 5, etc. negative gradient
slopes could be defined. In such a case, the FMCW radar
23
transceivers would also need to observe this convention
and alternate their chirping directions.
One way for such a system to operate would be using an externally deriving timing reference as mentioned above, which may for example be from GNSS. In such cases, the control unit 208 may receive the GNSS signal and distribute this to the radar transceivers 201, 202, 203, 204, 205. Alternatively the control unit 208 may directly control the chirp timing as well as frequency. Radar transceivers 201, 202, 203, 204, 205 around the vehicle 200 typically use a crystal oscillator with a precision on the order of 50 parts per million. Hence even if the start time of the chirp is precise, there may be an offset in the frequency.
embodiments the radar
204, 205
under
202,
For this reason
201,
SOITIG
transceivers 203, use the timing
reference to correct their internal clocks. For example if
the radar could determine the clock error and correct the frequency controlling parameters accordingly such that the
start frequency was always precise.
The radar transceivers 201, 202, 203, 204, 205 may operate
using such a timeslot structure without the use of a GNSS
reference and in such cases they could monitor the
surrounding signals and select a timeslot in the same way.
However such a system. would. be less precise and the
timeslots may not be used as efficiently. Similarly in some situations the GNSS signal may be lost temporarily or such as in a tunnel and in such cases
202, 203, 204, 205 would need
for a longer time, the radar transceivers 201,
to use their best estimates of the last good timing and be
24
aware that their neighbouring vehicles would have similar
limitations.
The described method may still operate quite well if a small percentage of the vehicles in the population did not have the external timing reference, but based the timing only on listening to the structure of the other radar transceivers that did use the frequency reference. There would still be benefit in the radar transceivers from using the same gradient without timing reference. In fact, those vehicles may be able to synchronise to the chirp of other external radar transceivers using for example a phase locked loop and hence derive their own internal frequency and timing reference.
The selection of timeslots may therefore, according to some aspects, be based on listen before talk or could be based either on the direction of the vehicle or based on the pointing direction of the radar transceivers 201, 202, 203, 204, 205 as discussed above.
202, 203, 204,
For example if the radar
transceiver 201, 205 is pointing' in a northerly direction, then the radar could select a timeslot from the set of 0, 8, 16 or 24.
201, 202, 203, 204,
If the radar transceiver 205 was facing west then it could select from timeslots 2, 10, 18, 26, etc. In this way a system could be developed that would be compatible both
with FMCW and stepped FMCW radar transceivers.
It may be that the defined total number of timeslots is different to 32 however the number 32 is used in this
disclosure as one example.
According to some aspects, all radar transceivers within
a vehicle may be synchronised in time and possibly also
frequency using a protocol such as PTP. The selection of
the timeslot may be based on first monitoring the band for a period of for example 64us before selecting a timeslot and starting transmissions or alternatively be based on
the compass direction of the main beam of the radar, for
example a radar pointing due north may use timeslot 0, a
radar pointing due west may use timeslot 8, etc. In other
words the timeslot number could be calculated directly from the direction of the radar in degrees relative to due
north.
Figure 11 schematically illustrates, in terms of a number
of functional units, the components of the control unit
208 according to an embodiment.
Processing circuitry 710 is provided using any combination
of one or more of a suitable central processing unit (CPU),
multiprocessor, microcontroller, digital signal processor
(DSP), dedicated hardware accelerator, etc., capable of
executing software instructions stored in a computer
program product, e.g. in the form of a storage medium 730.
The processing circuitry 710 may further be provided as at
least one application specific integrated circuit (ASIC),
or field programmable gate array (FPGA).
Particularly, the processing circuitry 710 is configured
to cause the control unit 208 to perform. a set of
operations, or steps. These operations, or steps, were
discussed above in connection to the various radar
transceivers and methods. For example, the storage medium
26
730 may store the set of operations, and the processing circuitry 710 may be configured to retrieve the set of operations from the storage medium 730 to cause the control unit 208 to perform the set of operations. The set of executable
710 is
operations may be provided as a set of
instructions. Thus, the processing circuitry
thereby' arranged. to execute methods and. operations as
herein disclosed.
The storage medium 730 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid
state memory or even remotely mounted memory.
The control unit 208 may further comprise a communications interface 720 for communications with at least one other unit. As such, the radar interface 720 may comprise one or more transmitters and receivers, comprising analogue and digital components and a suitable number of ports for wired or wireless communication.
The processing circuitry 710 is adapted to control the general operation of the control unit 208 e.g. by sending data and control signals to the external unit and the storage medium 730, by receiving data and reports from the external unit, and by retrieving data and instructions
from the storage medium 730. Other components, as well as
the related functionality, of the control unit 208 are omitted in order not to obscure the concepts presented
herein.
27
Generally, the control unit 208 is adapted to communicate
with at last one external unit 400, 420, 430, 450. This
can for example be enabled by means of a satellite receiver 206 and/or a cellular network receiver 207 which are comprised in the radar system 210 as shown in Figure 10, and which are connected to the communications interface
720.
Figure 12 shows a computer program product 810 comprising
computer executable instructions 820 arranged on a
computer readable medium 830 to execute any of the methods
disclosed herein.
With reference to Figure 13, the present disclosure also
relates to a næthod in vehicle radar system 210; 210A,
210B, 210C. The method comprises generating and
transmitting S100 an FMCW, Frequency Modulated Continuous Wave, signal 220 in a radar frequency band using at least one radar transceiver arrangement 201, 202, 203, 204, 205, and receiving S200 reflected signals 221 that have been
reflected by one or more target objects 222.
Each FMCW signal 220 comprises a corresponding plurality
of ego frequency' ramps r; ra, rb, rc, rd, re that are
generated in radar cycles having a certain ego cycle time
tc and ego cycle start time tas; tcsa, tcsb, tcsc, tcsd, tcse.
Each one of the ego frequency ramps r; ra, rb, rc, rd, re has a certain ego duration time tr, an ego delay time tD between adjacent ego frequency ramps r and an ego frequency
gradient df/dt.
28
The method further comprises receiving S300
information. fron1 at least one external
430, 450; 208A, 208B, 208C; 460,
synchronization
unit 400, 420, and basing
S400 at least the ego cycle start time tæ;
tcsa/ tcsb/ tcsc/
tcw, tcæ, the ego duration time tr and the ego delay time
tD on the synchronization information.
According to some aspects,
S500
the næthod comprises basing
the ego frequency gradient df/dt on the
synchronization information.
According to some aspects, the synchronization information
comprises time reference data, where the method comprises
controlling the ego cycle start time tæ; tcæ, tcw, tcæ,
tcw, tcæ in dependence of the time reference data.
According to some aspects, the synchronization information
comprises a frequency reference, where the method comprises controlling at least one radar transceiver arrangement 201, 202, 203, 204 205 to generate ego
frequency ramps r; ra, rb, rc, rd, re in dependence of the
frequency reference.
Each radar system 210, 210A, 210B, 210C is adapted to monitor the radar band in one or more of the pre-defined timeslots to determine the best timeslot to select for transmissions. The timeslot corresponding to a periodic allocation within a defined period.
According to some aspects, the present disclosure relates to a common vehicle radar system 900 comprising at least
two separate radar systems 210; 210A, 210B, 210C, 210D.
29
Each radar system 210; 210A, 210B, 210C, 210D comprises a
at least radar transceiver
203,
and
202,
control unit 208 one
arrangement 201, 204 205 arranged to generate
and transmit an FMCW, Frequency Modulated Continuous Wave, signal 220 and to receive reflected signals 221 that have
been reflected by one or more target objects 222. The FMCW
signal 220 comprises a corresponding plurality of
frequency ramps r; ra, rb, rc, rd, re; ri that are generated
in radar cycles having a certain cycle time tc and cycle
Start time tcsr' tcsa/ tcsb/ tcsc/ tcsd/ tcse; tcsil- tcsi4- Each
one of the frequency ramps r has a certain duration time tr, delay time tD between adjacent the frequency ramps r and frequency gradient df/dt. All the ramps r; r¿, rb, rm rd, re; ri generated in the vehicle radar system share the
same duration time tr, delay time tD, and
df/dt,
cycle time tc,
frequency gradient where, for each radar
transceiver arrangement, each cycle start time tcfi
tCSäI
tcsb/ tcsc/ tcsd/ tcse; tcsil- tcsi4 is different-
According to some aspects, the present disclosure relates to a radar system 210 for a vehicle 200,
203,
comprising a 204, 205 and a 203, 204,
plurality of radar transceivers 202, control unit 208. Each radar transceiver 202, 205 occupies one or more of a defined set of interleaved timeslots to avoid interference and to minimise interference to neighbouring vehicles. The timeslot allows the UE to send nmltiple chirps periodically within one radar cycle.
In the case of stepped FMCW radar, the radar transceivers
within the vehicle also occupy a minimum set of timeslots
by ensuring their start times and start frequencies are
precisely controlled within a vehicle. The timing reference and optionally also the starting frequency of each timeslot would be obtained from an external frequency reference, e.g. GNSS. The timeslot used by each radar may be determined by each radar using a listen-before-talk approach or using the compass direction of the vehicle.
The present disclosure is not limited to the above, but may vary freely within the scope of the appended claims. For example, each control unit 208; 208A, 208B, 208C, 208D may be in the form of a control unit arrangement that is constituted by one or more control unit parts that can be separate from each other. Some or all control unit parts may be comprised in a corresponding radar transceiver 201, 202, 203, 204, 205 and/or remote server 430.
When the radar transceivers 20l, 202, 203, 204, 205 are
positioned. in a vehicle 200, the control unit 208 is according to some aspects at least partly positioned in
the same vehicle.
Each radar transceiver can also be regarded as a radar
transceiver arrangement.
Chirp, radar chirp and frequency ramp are normally mutually
equivalent regarding technical meaning' in the present
context.
Claims (15)
1. A vehicle radar system (210; 210A, 210B, 210C) comprising a control unit (208) and at least one radar transceiver arrangement (201, 202, 203, 204, 205) arranged to generate and. transmit an FMCW, (220) Frequency' Modulated Continuous Wave, signal in a radar frequency band (221) that have been (222), and. to receive reflected. signals reflected by one or more target objects where each FMCW signal (220) comprises a corresponding plurality of ego frequency ramps (r; ra, rb, rc, rd, re) that are generated in radar cycles having a certain ego cycle time (tC) (tCSI. tCSG) I rc, rd, re) and ego cycle start time tcsa/ tcsb/ tcsc/ tcsd/ where each one of the ego frequency ramps (r; ra, rb, (tf) , between adjacent ego frequency ramps (r) (df/dt), (208) is has a certain ego duration time (th) and an ego frequency gradient an ego delay time characterized in that the control unit adapted to receive information. fron1 at least one external 430, 450; 208A, 208B, synchronization unit (400, 420, 208C; and to (tcsf 460), base at least the ego cycle start time tcsa/ tcsb/ tcsc/ tæd, tæe), the ego duration time (tr) and the ego delay time (tD) on the synchronization information.
2. The vehicle radar system. (210; 210A, 210B, 210C) according to claim 1, (df/dt) wherein the ego frequency gradient is based on the synchronization information.
3. The vehicle radar system. (210; 210A, 210B, 210C) according to any one of the claims 1 or 2, wherein the synchronization information comprises time reference data, (208) where the control unit is adapted to control the egocycle Start time (tcsf tcsa/ tcsb/ tcsc/ tcsd/ tcse) in dependence of the time reference data.
4. The vehicle radar system. (210; 210A, 210B, 210C) according to any one of the previous claims, wherein the information comprises a (208) is synchronization frequency adapted to (201, reference, where the control unit control at least one radar transceiver arrangement 202, 203, 204 205) to generate ego frequency ramps (r; ra, rg, rc, rd, re) in dependence of the frequency reference.
5. The vehicle radar system. (210; 210A, 210B, 210C) according to any one of the previous claims, wherein the synchronization information comprises information regarding' at which. times (tcßi, tcæz, tcæs, tcwi) neighboring radar transceivers are transmitting neighboring frequency ramps (ri; rn, ru, rm, rfl) and with which neighboring frequency gradient (df/dt), where the control unit (208) (df/dt) to is adapted to control the ego frequency gradient correspond. to the synchronization information and to schedule the ego frequency ramps (r; ra,;QN rC,1@, Lg in free timeslots between the neighboring frequency ramps (ri; rn, ru, rm, rfl).
6. The vehicle radar system. (210; 210A, 210B, 210C) according to any one of the previous claims, wherein the control unit (208) is adapted to - control at least one radar transceiver arrangement (201, 202, 203, 204, 205) to monitor a certain part of the radar frequency band during an observation period;- analyze possible interference signals (ri; rih rn, E13, Ii4),' and tO - identify a certain start time (tca tæa, tæb, tcæ, tCSG) frequency ramps (r; ra, rb, rc, rd, rg tcw, to start sending a cycle of one or more ego in dependence of said analysis, such that interference from said interference signals (ri; rn, rn, rm, rfl) is reduced.
7. The vehicle radar system. (2l0; 2l0A, 2l0B, 2l0C) according to any one of the previous claims, wherein the control unit (208) is adapted to receive information from neighboring control units (208A, 208B, 208C, 208D) regarding neighboring timeslots (TSH, TSih TSÜ, TSi@ and to determine an ego timeslot structure with corresponding ego timeslots (TSA, TSB; TS1, TS9, TSU).
8. The vehicle radar system. (2l0; 2l0A, 2l0B, 2l0C) wherein each 204, 205) is according to any one of the previous claims, radar transceiver arrangement (201, 202, 203, associated with a main pointing direction (F, Pl, P2, P3, P4) and a pre-defined set of timeslots 0..N, where each timeslot corresponds to a sequence of ego frequency ramps (r; ra, rb, rc, rd, re) within a frame and the timeslot number corresponds to a time offset, where the control unit (208) is adapted to: which divide a full (3l0), - define heading intervals 360° (3l0) turn interval 0°- into sections - assign a corresponding timeslot to (3l0), each heading interval - determine a present vehicle heading and to (F),- assign a corresponding timeslot to each one of the radar transceivers (201, 202, 203, 204, 205) in dependence of the heading interval (310) that comprises the present vehicle heading (F).
9. The vehicle radar system. (210; 210A, 210B, 210C) wherein the 203, 204, 205) according to any one of the previous claims, radar transceiver arrangements (201, 202, are adapted to transmit a stepped FMCW waveform whereby the radar transceiver arrangements (201, 202, 205) 203, 204, are synchronised. such. that the corresponding' ego frequency ramps (r; ra, rb, rc, rd, re) are aligned to occupy one timeslot (TS1, TS9, TSU) each.
10. The vehicle radar system. (210; 210A, 210B, 210C) according to claim 9, wherein the slope of the timeslots (TS1, TS9, TSU) is positive in some stepped frequency radar cycles (Ca-CG) and negative in some stepped frequency radar cycles (C'a-C'e).
11. A method in vehicle radar system (210; 210A, 210B, 210C), the method comprising generating and transmitting (S100) an FMCW, Frequency Modulated Continuous Wave, signal (220) in a radar frequency band using at least one radar transceiver arrangement (201, 202, 203, 204, 205); and receiving' (S200) reflected. signals (221) that have been reflected by one or more target objects (220) (222); where each FMCW signal comprises a corresponding plurality of ego frequency ramps (r; ra, rb, rc, rd, rg that are generated in radar cycles having a certain ego cycle time (tc) and ego cycle start time (tcfi tcsa/ tcsb/ tCSG) I (r; rar rb/ rc/ rdr where each one of the ego frequency ramps (tf), (tD) between adjacent ego frequency ramps (df/dt), tcsc/ tcsd/ ré) has a certain ego duration time an ego delay time (r) and an ego frequency gradient characterized in that the method further comprises receiving (S300) synchronization information from at least one external unit (400, 420, 430, 450; 208A, 208B, 208C; 460), and basing (S400) (tæ; and at least the ego cycle start time tcsd/ tcse) r (tr) (tD) on the synchronization information. tcsb/ tcsc/ tæa, the ego duration time the ego delay time wherein the method (df/dt)
12. The method according to claim 11, comprises basing (S500) the ego frequency gradient on the synchronization information.
13. The method according to any one of the claims 11 or 12, wherein the synchronization information comprises time reference data, where the method comprises controlling the (t@S; dependence of the time reference data. ego cycle start time tcfiu tcüfl tcyn tcfih tC¶Q in
14. The method according to any one of the claims 11-13, wherein the synchronization information comprises a frequency reference, where the method comprises controlling' at least one radar transceiver* arrangement (201, 202, 203, 204 205) to generate ego frequency ramps (r; ra, rb, rc, rd, re) iJ1 dependence (If the frequency reference.
15. A vehicle (210) (200) comprising the vehicle radar system according to any one of the claims 1-10.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE2251059A SE2251059A1 (en) | 2022-09-13 | 2022-09-13 | An fmcw radar system with increased capacity |
PCT/EP2023/074573 WO2024056511A1 (en) | 2022-09-13 | 2023-09-07 | An fmcw radar system with increased capacity |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE2251059A SE2251059A1 (en) | 2022-09-13 | 2022-09-13 | An fmcw radar system with increased capacity |
Publications (1)
Publication Number | Publication Date |
---|---|
SE2251059A1 true SE2251059A1 (en) | 2024-03-14 |
Family
ID=88018162
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
SE2251059A SE2251059A1 (en) | 2022-09-13 | 2022-09-13 | An fmcw radar system with increased capacity |
Country Status (2)
Country | Link |
---|---|
SE (1) | SE2251059A1 (en) |
WO (1) | WO2024056511A1 (en) |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1775600A1 (en) * | 2004-08-02 | 2007-04-18 | Mitsubishi Electric Corporation | Radar apparatus |
EP3244229A1 (en) * | 2016-05-13 | 2017-11-15 | Autoliv Development AB | A vehicle radar system arranged for interference reduction |
EP3306339A1 (en) * | 2016-10-07 | 2018-04-11 | Autoliv Development AB | A vehicle radar system arranged for interference reduction |
US20180149730A1 (en) * | 2016-11-26 | 2018-05-31 | Wenhua Li | Cognitive MIMO Radar with Multi-dimensional Hopping Spread Spectrum and Interference-Free Windows for Autonomous Vehicles |
US20210003662A1 (en) * | 2019-07-03 | 2021-01-07 | Chalmers Ventures Ab | Method for reducing mutual interference in radars |
EP3865896A1 (en) * | 2020-02-11 | 2021-08-18 | Veoneer Sweden AB | A radar transceiver |
EP3869221A1 (en) * | 2020-02-20 | 2021-08-25 | Veoneer Sweden AB | A radar system with sub-bands |
US20220091251A1 (en) * | 2020-09-22 | 2022-03-24 | Semiconductor Components Industries, Llc | Fast chirp synthesis via segmented frequency shifting |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8797208B2 (en) * | 2010-12-13 | 2014-08-05 | Sony Corporation | Active radar system and method |
JP5511863B2 (en) * | 2012-02-03 | 2014-06-04 | 三菱電機株式会社 | Radar apparatus and control method thereof |
US9720072B2 (en) * | 2014-08-28 | 2017-08-01 | Waymo Llc | Methods and systems for vehicle radar coordination and interference reduction |
-
2022
- 2022-09-13 SE SE2251059A patent/SE2251059A1/en unknown
-
2023
- 2023-09-07 WO PCT/EP2023/074573 patent/WO2024056511A1/en unknown
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1775600A1 (en) * | 2004-08-02 | 2007-04-18 | Mitsubishi Electric Corporation | Radar apparatus |
EP3244229A1 (en) * | 2016-05-13 | 2017-11-15 | Autoliv Development AB | A vehicle radar system arranged for interference reduction |
EP3306339A1 (en) * | 2016-10-07 | 2018-04-11 | Autoliv Development AB | A vehicle radar system arranged for interference reduction |
US20180149730A1 (en) * | 2016-11-26 | 2018-05-31 | Wenhua Li | Cognitive MIMO Radar with Multi-dimensional Hopping Spread Spectrum and Interference-Free Windows for Autonomous Vehicles |
US20210003662A1 (en) * | 2019-07-03 | 2021-01-07 | Chalmers Ventures Ab | Method for reducing mutual interference in radars |
EP3865896A1 (en) * | 2020-02-11 | 2021-08-18 | Veoneer Sweden AB | A radar transceiver |
EP3869221A1 (en) * | 2020-02-20 | 2021-08-25 | Veoneer Sweden AB | A radar system with sub-bands |
US20220091251A1 (en) * | 2020-09-22 | 2022-03-24 | Semiconductor Components Industries, Llc | Fast chirp synthesis via segmented frequency shifting |
Non-Patent Citations (2)
Title |
---|
Aydogdu, C., Keskin, F., Carvajal, G. et al (2020). 'Radar Interference Mitigation for Automated Driving: Exploring Proactive Strategies'. IEEE Signal Processing Magazine, 37(4): 72-84. http://dx.doi.org/10.1109/MSP.2020.2969319 * |
Khurram Usman Mazher; Robert W. Hearth Jr.; Kapil Gulati; Junyi Li, 'Automotive Radar Interference Characterization and Reduction by Partial Coordination', IEEE Radar Conference, 2020, ISBN: 978-1-7281-8942-0 * |
Also Published As
Publication number | Publication date |
---|---|
WO2024056511A1 (en) | 2024-03-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4593286A (en) | Method of operating an agile beam coherent radar | |
CA2634506A1 (en) | High-resolution synthetic aperture radar device and antenna for a high-resolution synthetic aperture radar device | |
CN112203350B (en) | Signal transmitting method and device | |
US20040204850A1 (en) | Automotive synchronized communication networks | |
JP2012054799A (en) | Communication apparatus | |
US11460539B2 (en) | Method and device for operating multiple sensors of a vehicle | |
US20220137179A1 (en) | Detection method and signal sending method and apparatus | |
EP3821268A1 (en) | Locating method for localizing at least one object using wave-based signals and locating system | |
EP3545504A1 (en) | Prediction based client control | |
CN113924508A (en) | Space Time Frequency Multiplexing (STFM) for radar systems using complementary pair waveforms | |
SE2251059A1 (en) | An fmcw radar system with increased capacity | |
EP3379869B1 (en) | Delay calculation in wireless systems | |
US10775479B2 (en) | Efficient non-interfering multi-radar transmission scheme | |
KR20220070535A (en) | Method for interference-free operation of multiple radar sensors | |
US20230084041A1 (en) | A radar system with sub-bands | |
JPH09113615A (en) | Interferometry sar system | |
CN111896959B (en) | Bistatic SAR phase synchronization precision improving method and device, electronic equipment and medium | |
US8130680B1 (en) | Method for timing a pulsed communication system | |
US8331888B2 (en) | Remote programmable reference | |
US20210199753A1 (en) | Synchronized radar networks | |
US10911094B1 (en) | Chirp sequence synthesis in a dynamic distribution network | |
JPH03105276A (en) | Radar apparatus | |
GB2564085A (en) | Method and apparatus for digital signal processing of a multichannel radar | |
RU2470489C1 (en) | Method of communication in monitoring and control of moving objects | |
JP7313525B2 (en) | ELECTRONIC DEVICE, ELECTRONIC DEVICE CONTROL METHOD, AND ELECTRONIC DEVICE CONTROL PROGRAM |