Radar device with increased bandwidth

Abstract

A radar device (100) is described herein, the radar device being a monostatic radar device, the radar device comprising: i) a first channel (121) having a first bandwidth and configured to receive a first radar signal; ii) a second channel (122) having a second bandwidth and configured to receive a second radar signal, where the first frequency band is different from the second frequency band; and iii) a control device (110) configured to: a) obtain a first channel response associated with a received first signal at the first channel (121); b) obtaining a second channel response associated with the received signal at the second channel (122); and c) combining the first channel response with the second channel response by channel stitching (112) to obtain a combined channel response (115).

Description

Technical Field

[0001] The present disclosure relates to a radar device having at least two channels, each channel being used for a different bandwidth (frequency range). Specifically, the radar device includes a control device configured to combine a received radar signal from a first channel with another received radar signal from a second channel by channel splicing. The present disclosure further relates to a method for operating such a radar device. Therefore, the present disclosure may relate to the technical field of radar devices, in particular the technical field of ultra-wideband (UWB) applications. Background Art

[0002] Radar operation uses radio frequency (RF) signals / waves to determine spatial properties of a target (an object of interest, such as a person or vehicle), such as location, distance, angle, or velocity. Thus, a transmitter transmits an RF signal toward the target, and one or more receivers obtain reflections (echoes) of the RF signal that have been reflected by the target. For example, ultra-wideband (UWB) wireless technology, which enables secure and accurate ranging with an accuracy of less than 5 cm, can also be used as a radar device for receiving reflected signals from targets. For example, a UWB device can be used as a pulse radar, in which a short-duration pulse is transmitted and its reflection is received. This reflection is captured as a change in the channel impulse response (CIR) measured by the receiver.

[0003] However, the performance of a radar system can often be limited by bandwidth, for example in the case of UWB radar systems, to the range of 0.5 to 1 GHz (for standardized IEEE channels). This limited bandwidth can affect i) the accuracy of ranging to individual targets and / or ii) the ability to resolve targets that are close to each other (radar resolution).

[0004] Figure 8 The channel response from a conventional radar device (radar multi-tap channel) is shown. The y-axis shows the amplitude, and the x-axis shows the path length (of the radar signal) in meters. At 0 meters (d0) (i.e., at the radar device itself), a self-interference peak is observed. This is due to the fact that the radar device is a monostatic radar device, where the transmitter and receiver are arranged at the same physical location—in other words, the transmitter and receiver are co-located. Therefore, the transmitter can interfere with the associated receiver. At a distance of approximately 3 meters, two targets (d1, d2) are present.

[0005] In many applications, such as UWB, the bandwidth is limited, for example, by the applied standard. In the current example, a standardized UWB bandwidth of B = 500 MHz is applied. The range of the target is estimated based on the measured peak in the channel response. It can be seen that: (A) a large range error at the self-interference peak; and (B) the two targets appear to be one and inseparable. The accuracy of the range estimate and the radar resolution directly depend on the applied bandwidth. In the current example, it can be seen that for a bandwidth of 500 MHz, the resolution and accuracy are not high enough. They may be quite low. One would like to use the largest possible bandwidth, but this may be limited by hardware and standardization.

[0006] Figure 9 The CIR of a conventional radar device shows large sidelobes next to the mainlobe. The y-axis shows amplitude, and the x-axis shows normalized delay. The mainlobe is associated with the actual peak to be determined (the mainlobe of the pulse used for target range estimation), while the sidelobes are quite undesirable and should be avoided / minimized (it may be desirable to use pulses with minimal sidelobes). In this example, the peak-to-sidelobe ratio (PSLR, described further below) of the sidelobes is approximately 17 dB, so that the waveform used exhibits sidelobes that may be misclassified. Summary of the Invention

[0007] There may be a need to improve radar devices, particularly in terms of accuracy and / or resolution.A radar device, a method and a method of use are provided.

[0008] According to an aspect of the present disclosure, a radar device, in particular a monostatic radar device (in which transmitter functionality and receiver functionality are integrated in the same entity, co-located) is described, comprising:

[0009] i) a first channel (e.g., channel 5 of the UWB standard) having a first frequency band (e.g., 6 to 7 GHz, centered around 6.5 GHz), the first channel being configured to receive a first radar signal (e.g., a first reflection of the first radar signal from the transmitter);

[0010] ii) a second channel (e.g., channel 6 of the UWB standard; specifically, adjacent to the first channel) having a second frequency band (e.g., 7 to 8 GHz, centered around 7.5 GHz), the second channel being configured to receive a second radar signal (e.g., a second reflection of the second radar signal from the transmitter) (the first radar signal and the second radar signal may be similar or different), wherein the first frequency band and the second frequency band are different (overlapping or non-overlapping); and

[0011] iii) a control device (e.g., a processor, a chip, an integrated circuit, etc.), the control device being configured to:

[0012] a) obtaining a first channel response (particularly a first channel impulse response and / or a first spectrum) associated with a received first signal at a first channel;

[0013] b) obtaining a second channel response (specifically a second channel impulse response and / or a second spectrum) associated with the received signal at the second channel; and

[0014] c) combining the first channel response with the second channel response by channel concatenation (specifically, subsequent coherent combining) to obtain a combined channel response (specifically, a combined spectrum).

[0015] According to another aspect of the present disclosure, a method of operating a radar apparatus (e.g., as described above), in particular a monostatic radar apparatus, is described, the method comprising:

[0016] i) obtaining a first channel response associated with a received first signal at a first channel having a first frequency band;

[0017] ii) obtaining a second channel response associated with a received signal at a second channel having a second frequency band,

[0018] wherein the first frequency band is different from the second frequency band; and

[0019] iii) combining the first channel response with the second channel response to obtain a combined channel response,

[0020] Combining includes channel splicing.

[0021] According to another aspect of the present disclosure, a method of using channel stitching for improving the resolution / accuracy of the channel impulse response (CIR) of an ultra-wideband radar device is described.

[0022] In this document, the term "channel splicing" (or frequency band splicing or spectrum splicing) may specifically refer to the process of combining multiple passband signals. Preferably, the splicing may include the subsequent and coherent combination of channel impulse responses with different frequency bands.

[0023] According to exemplary embodiments, the present disclosure may be based on the idea that when the bandwidth (frequency band) is increased by channel splicing the channel responses of two or more channels of a radar device, the performance of the radar device may be improved, in particular in terms of accuracy and / or resolution. In this way, the bandwidth may be significantly increased (e.g., fourfold) while the accuracy / resolution may be greatly increased, see e.g. Figures 4 to 9 Based on the increased bandwidth, in a preferred example, additional processing schemes (such as shape filtering) can be applied to reduce the side lobes of the combined (stitched) spectrum next to the main lobe, thereby further increasing the performance.

[0024] In one embodiment, the present disclosure extends the bandwidth, which linearly reduces the bias of the range estimate (processing Figure 8 problem (A)), and also linearly reduces the resolvable distance between two or more targets (processing Figure 8 question (B)).

[0025] The aspects defined above and further aspects of the disclosure are apparent from the examples of embodiment to be described hereinafter and are explained with reference to these examples of embodiment.The disclosure will be described in more detail hereinafter with reference to examples of embodiment but to which the disclosure is not limited.

[0026] Exemplary embodiments

[0027] According to one embodiment, the first frequency band and the second frequency band are adjacent to each other (or neighboring). Specifically, there may be no other frequency bands (or channels) between them. In one embodiment, the first channel and the second channel are adjacent channels, such as, for example, channel 5 and channel 6 of the IEEE standard (e.g., IEEE 802.15.4-2020, specifically Section 15.4.1). In one example, additional frequency bands of additional channels may also be adjacent. Thus, using existing architectures, particularly efficient channel splicing can be achieved.

[0028] According to one embodiment, the radar device is an ultra-wideband (UWB) radar device. As a result, established and economically important standards can be directly applied.

[0029] In the context of this document, the term "ultra-wideband" may refer to a radio technology that enables short-range, high-bandwidth communications using very low energy levels across a large portion of the radio spectrum. Ultra-wideband may refer to a technology used to transmit information spread across a large bandwidth (e.g., 500 MHz). UWB can be defined as antenna transmissions where the transmitted signal bandwidth exceeds the smaller of 500 MHz or 20% of the arithmetic center frequency. UWB transmissions can transmit information by generating radio energy at specific time intervals and occupying a large bandwidth, thereby implementing pulse positioning or time modulation. The range of UWB can be, for example, in the tens of meters. UWB (RF) ranging systems can use the time-of-flight principle to determine the distance between a mobile device and a target device (e.g., a car to be opened) and / or an anchor device (tag) on ​​the target device. Typically, a transceiver's transmitter emits a waveform, typically a chirp or pulse, that is reflected by an object or retransmitted by a second transceiver. Based on the amount of time it takes for the reflection or retransmission to reach the initiating transceiver's receiver, the distance between the objects can be calculated. The range between the receiver and the transmitter thus determined is then used as a control point (to enable access). In the same manner, UWB may be used to transmit payloads.

[0030] In this context, “UWB” may include impulse radio ultra-wideband (IR-UWB) (see, for example, standards IEEE 802.15.4a and IEEE 802.15.4z). In another embodiment, another radar solution (particularly according to a certain standard) may be applied, for example based on WiFi, Bluetooth, RFID, etc.

[0031] According to one embodiment, the control device is further configured to: in particular by aligning (steering ) process calibrates the first channel response and the second channel response. To perform channel stitching of two or more channels (responses), alignment can improve accuracy and reliability.

[0032] According to an embodiment, the first channel response includes a first self-interference peak, and / or the second channel response includes a second self-interference peak (see, e.g. Figure 8 Specifically, the calibration / alignment process includes aligning a first self-interference peak and a second self-interference peak. In other words, the first channel response and the second channel response are calibrated based on a first phase of the first self-interference peak and / or a second phase of the second self-interference peak. Therefore, the phase (phase offset) of the CIR can be aligned based on the self-interference peak / phase.

[0033] In the context of this article, the term "self-interference" may refer to signals that are not caused by a target but rather by signal interference within a radar device. An example might be interference between the transmitter and receiver of the radar device. This self-interference may also be referred to as spillover, cross-coupling, crosstalk, etc. Figure 8 A specific example of self-interference is shown in FIG. Within the CIR, one or more self-interference peaks may be visible. Based on the one or more self-interference peaks, a self-interference phase may be determined, and calibration may be performed based on the self-interference phase.

[0034] According to one embodiment, the radar apparatus is further configured to process at least one of the first channel response, the second channel response, and the combined channel response. Using one or more processing schemes, the radar apparatus output quality (specifically, resolution / accuracy) can be further improved. In a preferred example, the processing can reduce / minimize side lobes immediately adjacent to the main lobe in the CIR. In one example, pre-processing and / or post-processing can be performed, for example, based on (spectral) filtering.

[0035] According to an embodiment, the processing comprises filtering to provide a specific / desired pulse shape, e.g. a Gaussian pulse shape (Gaussian (wave) form). According to an embodiment, the processing comprises pre-processing at least one of the first channel response and the second channel response by transforming into a raised cosine form, in particular before the splicing step. According to an embodiment, the processing comprises applying a Gaussian filter to the combined channel response (in particular after the splicing step). According to an embodiment, the processing comprises post-processing the combined channel response by transforming into a specific / desired shape, in particular a Gaussian waveform. The described processing steps may be performed individually or (partially) in combination with each other. In this way, side lobes may be reduced / minimized, see e.g. Figures 4 to 9 .

[0036] According to one embodiment, the radar device includes three or more channels (four or more), wherein the control device is configured to combine the corresponding three or more channel responses by channel splicing. For example, using four channels, the bandwidth can be four times the bandwidth of a single channel (e.g., 2 GHz instead of 500 MHz).

[0037] According to one embodiment, the radar device further comprises:

[0038] i) a transmitter for transmitting the (first and / or second) radar signal, and

[0039] ii) a receiver for receiving reflections of the radar signal (from the one or more targets). Specifically, the receiver includes a first channel and a second channel. In one example, the receiver includes a first receiver unit having the first channel and a second receiver unit having the second channel. This allows for a straightforward monostatic radar device.

[0040] According to an embodiment, at least one of the first self-interference peak / phase and the second self-interference peak / phase is at least partially generated by coupling between the transmitter and the receiver.

[0041] According to an embodiment, the transmitter is associated with the receiver. According to an embodiment, the transmitter and the receiver share a common antenna. According to an embodiment, the transmitter and the receiver are implemented in the same unit or in different units. According to an embodiment, the transmitter and the receiver are co-located.

[0042] According to one embodiment, a radar system is described, comprising:

[0043] i) a radar apparatus as hereinbefore described; and

[0044] ii) a target from which a radar (RF) signal is reflected, wherein the target is a moving target or a fixed target.

[0045] According to one embodiment, the first channel response is a first channel impulse response (CIR), and / or the second channel response is a second CIR. According to one embodiment, the first channel response is associated with a first spectrum, and / or the second channel response is associated with a second spectrum. According to one embodiment, the combined channel response is associated with a combined spectrum. According to one embodiment, the radar device (specifically, the channel) is configured according to an IEEE standard. For example, IEEE 802.15.4-2020, Chapter 15.4.1, which describes the RF requirements of the HRPUWB PHY standard. These features can (alone or in combination) enable implementation in technically and economically important applications.

[0046] According to one embodiment, the peak sidelobe ratio (PSLR) of the combined channel response is 20 dB or higher (specifically, 30 dB or higher, more specifically 40 dB or higher). In other words, the present disclosure can make it possible to significantly reduce the sidelobes adjacent to the mainlobe in the CIR. Conventionally, UWB radar sidelobe reduction methods operate in the angular domain, that is, antenna array processing is applied. However, the present disclosure can work with a single CIR measurement. The PSLR can be calculated, for example, as: PSLR = |s(0)| / |s(τ p1 )|, where τ p1 will be the time of the first side lobe (τ p0 = 0 mainlobe). A positive value (e.g., +20 dB) can be used for PSLR since it is the peak divided by the sidelobe power.

[0047] The given formula assumes that tau = 0 is the location of the main lobe (see also Figure 4 and 9 ).

[0048] According to one embodiment, the method further includes applying the combined channel response to determine spatial characteristics. This allows for efficient and reliable determination of spatial characteristics. Spatial characteristics may include the position / location of targets in space, distance to targets, number of targets, velocity of targets, and the like. Methods such as time difference of arrival (TDoA) or angle of arrival (AoA) may be used.

[0049] In the context of this document, the term "target" may specifically refer to an entity (e.g., an object, a person, an animal, etc.) to be investigated by radar, specifically with respect to spatial characteristics such as location and velocity. Thus, a "target peak" may be a detected response signal caused by reflections of a transmitted RF signal from a target. For example, the CIR may be calculated based on the reflections of the RF signal, and the target peak may be one or more peaks in the CIR resulting from reflections at the target. Based on the target peaks, the target phase (the phase of the received reflected RF signal) may be determined.

[0050] According to an embodiment, multiple (UWB) sub-band measurements are combined such that in the described radar apparatus a continuous switching / sweeping of these frequency bands can be detected in a straightforward manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A radar device according to an exemplary embodiment of the present disclosure is shown.

[0052] Figure 2 A first processing scheme before stitching according to an exemplary embodiment of the present disclosure is shown.

[0053] Figure 3 A second processing scheme after stitching according to an exemplary embodiment of the present disclosure is shown.

[0054] Figure 4 and 6 Different channel impulse responses according to exemplary embodiments of the present disclosure are respectively compared.

[0055] Figure 5 and 7 Different baseband spectra according to exemplary embodiments of the present disclosure are respectively compared.

[0056] Figure 8 A comparison of channel impulse responses from a conventional device and a radar device according to an exemplary embodiment of the present disclosure is shown.

[0057] Figure 9 A comparison of side lobes beside a main lobe of a conventional apparatus and a radar apparatus according to an exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0058] Before describing the embodiments in more detail with reference to the drawings, some basic considerations upon which embodiments of the present disclosure have been developed will be outlined.

[0059] According to an exemplary embodiment, the present disclosure may take UWB channel impulse response (CIR) measurements as input to expand the radar system's available bandwidth in two steps:

[0060] 1) Subsequent coherent combining of multiple frequency bands (channel stitching), involving a simple calibration procedure (aligning the self-interference between channels and calibrating their phases).

[0061] 2) Spectral shaping filtering as pre-processing or post-processing to obtain a favorable pulse shape.

[0062] Processing may, for example, include:

[0063] i) Transform the a priori known single-band spectra into raised cosine (preprocessing) and apply a Gaussian filter after concatenation.

[0064] ii) Converting the a priori known spliced ​​spectrum into a Gaussian waveform spliced ​​spectrum (post-processing).

[0065] The resulting CIR-based radar signal comprises pulses with a narrow main lobe (via step 1) while keeping the side lobes within reasonable limits (via step 2).

[0066] Figure 1 A radar device 100 according to an exemplary embodiment of the present disclosure is shown. Radar device 100 includes a control device 110 (e.g., one or more processors) coupled (directly or remotely, e.g., by wire or wirelessly) to a plurality of channels 120 (channel inputs). Radar device 100 in this example is a UWB radar device configured to comply with IEEE standards. A transmitter (not shown in this example) of radar device 100 is co-located with a receiver, as illustrated by input channels 120. Radar device 100 is a monostatic radar device, with the transmitter and receiver 120 being located on the same physical body. The transmitter transmits one or more radar signals, which are then reflected by a target. The reflected radar signals are then received by the channels of receiver 120.

[0067] In this example, receiver 120 includes four channels: a first channel 121 having a first frequency band, a second channel 122 having a second frequency band, a third channel 123 having a third frequency band, and a fourth channel 124 having a fourth frequency band. In this example, IEEE standard baseband channels 5, 6, 8, and 9 are applied (channel 7 is not included because it is a 1 GHz channel with the same center frequency as channel 5). It should be noted that these channels 121-124 are adjacent to each other, that is, there is no gap between them in terms of bandwidth. First channel 121 is configured to receive a first radar signal, second channel 122 is configured to receive a second radar signal, and so on. The radar signal can be the same for all channels or different for each channel 121-124. First channel 121 measures a first channel response as a first channel impulse response, second channel 122 measures a second channel response as a second channel impulse response, and so on. These channel impulse responses are then transmitted to control device 120.

[0068] The control device 110 is configured to obtain the channel impulse response (CIR) and combine the first CIR, the second CIR, the third CIR and the fourth CIR by channel splicing 112 to obtain a combined channel (impulse) response 115 (i.e., a combined spectrum) as output. Figure 1 As can be seen in FIG, channel splicing 112 is based on the number of frequency bands (n) and the center frequency (f st) for adjacent frequency bands: n*f st ,in

[0069] f st =f (1) st +ΔB i

[0070] In order not to lose information, the sampling rate can be scaled with the number of frequency bands when computing the output sum 113, e.g., resampling T s ->T s / N B .

[0071] Before performing the actual channel stitching 112, calibration 111 is applied to align the first CIR, the second CIR, the third CIR and the fourth CIR with each other. In order to perform such alignment, it is necessary to estimate the parameters (steering vectors) Since the radar device 100 is a monostatic radar device in this example, in which the transmitter and the receiver are co-located, a self-interference peak (SI) caused by the interference between the transmitter and the receiver can be observed in each CIR (see also Figure 8 ). The self-interference peak (caused by the same device, i.e., device-specific) exists in all four CIRs, so that the CIR phase offset can be aligned to zero based on the phase of the self-interference.

[0072] Figure 2 A first processing scheme according to an exemplary embodiment of the present disclosure is shown, which refers to the processing (preprocessing) of the corresponding CIR (spectrum) before channel splicing. Each input spectrum (from the corresponding channel 121-124) is preprocessed by a raised cosine equalization filter. The single sideband spectrum is known a priori, and the RC signal produces a flat stitch spectrum. The bandwidth is selected so as to cover the support of the channel splicing. After the channel splicing step 112, a Gaussian filter is applied to the combined response to provide a processed combined spectrum 115. This processing scheme achieves very low sidelobes in both the time domain and the frequency domain.

[0073] Figure 3 A second processing scheme according to an exemplary embodiment of the present disclosure is shown, which refers to processing (post-processing) of the combined CIR (combined spectrum) after channel splicing. After the splicing step 112, Gaussian equalization is applied to the combined CIR to obtain a processed combined spectrum 115. Thus, a clean splice can be obtained from the known single-sideband spectrum, and the non-ideal shape (ripple, roll-off) of the spliced ​​frequency band can be compensated.

[0074] Figure 4Four different CIRs are shown to compare the conventional method with the exemplary embodiments of the present disclosure. The y-axis shows the normalized amplitude in dB, while the x-axis shows the path length in meters (compare the CIRs described above). Figure 8 A one-meter cable measurement is performed to simulate a single target, where the CIR of one or more IEEE standardized channels is measured over an open cable (at double the length of the cable) to generate reflections. At 0 meters, there is a self-interference peak, while at 1 meter (2m round trip), the target is located.

[0075] i) First, as is conventionally done, only one channel (here channel 5) is applied (single band).

[0076] ii) Furthermore, according to the present disclosure, adjacent channels 5 to 9 have been used for channel splicing (four frequency bands).

[0077] Additionally, the combined spectrum has:

[0078] iii) processed by a raised cosine equalization filter (see also Figure 2 ),as well as

[0079] iv) Processing by Gaussian equalization (see also Figure 3 ).

[0080] It can be seen that the resolution and accuracy of the CIRs (ii to iv) according to the present disclosure are significantly improved compared to the conventional CIR (i).

[0081] Figure 5 Shown with Figure 4 The baseband spectra corresponding to the CIR measurement results are shown in Figure 1. The conventional spectrum i) covers a bandwidth of 500 MHz, while the combined spectra ii) to iv) each cover a bandwidth of 2 GHz (four times larger).

[0082] Figure 6 Four different CIRs are shown to compare the conventional method with the exemplary embodiments of the present disclosure. Figure 4 In contrast, a cable with a splitter measurement was used to simulate a dual target (two targets). Thus, one or more channels were used above two open cables via splitters (50 cm and 75 cm) to observe the target peaks at 0.5 m (1 m round trip) and 0.75 m (1.5 m round trip). It can be seen that with conventional CIR (i), the targets cannot be separated. However, using CIR (ii to iv) according to the present disclosure, a clear separation can be achieved (due to the higher resolution).

[0083] Figure 7 Shown with Figure 6The baseband spectra corresponding to the CIR measurement results are shown in Figure 1. The conventional spectrum i) covers a bandwidth of 500 MHz, while the combined spectra ii) to iv) each cover a bandwidth of 2 GHz (four times larger).

[0084] for Figure 8 , the conventional example has been described above. However, according to the present disclosure, a bandwidth of B=2 GHz can be applied, and the resolution and accuracy can be significantly improved; specifically, two targets can be separated, and the target distance can be accurately estimated.

[0085] for Figure 9 , a conventional example has been described above. However, according to the present disclosure, and in particular using the described processing scheme, it is possible to improve resolution and accuracy.

Claims

1. A radar device (100), which is a monostatic radar device, characterized in that: include: a first channel (121) having a first frequency band and configured to receive a first radar signal; a second channel (122) having a second frequency band and configured to receive a second radar signal, wherein the first frequency band is different from the second frequency band; and A control device (110) configured to: obtaining a first channel response associated with a received first signal at the first channel (121); obtaining a second channel response associated with the received signal at the second channel (122); as well as The first channel response is combined with the second channel response by channel concatenation (112) to obtain a combined channel response (115).

2. The radar device (100) according to claim 1, characterized in that The first frequency band and the second frequency band are adjacent to each other.

3. The radar device (100) according to claim 1 or 2, characterized in that The radar device (100) is an ultra-wideband (UWB) radar device.

4. The radar device (100) according to any of the preceding claims, characterized in that The control device (110) is further configured to: The first channel response and the second channel response are calibrated (111) through an alignment process.

5. The radar device (100) according to claim 4, characterized in that The first channel response includes a first self-interference peak, The second channel response includes a second self-interference peak, and The alignment process includes: The first self-interference peak is aligned with the second self-interference peak.

6. The radar device (100) according to any of the preceding claims, characterized in that The control device (110) is further configured to: At least one of the first channel response, the second channel response, and the combined channel response (115) is processed.

7. The radar device (100) according to claim 6, characterized in that The processing includes filtering to provide a specific pulse shape.

8. The radar device (100) according to claim 6 or 7, characterized in that: Also includes at least one of the following features: preprocessing at least one of the first channel response and the second channel response by transforming into a raised cosine form; applying a Gaussian filter to the combined channel response (115); The combined channel response is post-processed by transforming into a Gaussian waveform.

9. A method of operating a radar device (100), the radar device being a monostatic radar device, characterized in that: The method comprises: obtaining a first channel response associated with a received first signal at a first channel (121) having a first frequency band; obtaining a second channel response associated with a received signal at a second channel (122) having a second frequency band, wherein the first frequency band is different from the second frequency band; and combining the first channel response with the second channel response to obtain a combined channel response (115), The combination includes channel splicing.

10. A method for channel splicing, characterized in that: Used to improve the channel impulse response (CIR) resolution of ultra-wideband (UWB) radar devices.

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