Intercell interference coordination for cellular sensing

Abstract

Systems and methods are described for environment sensing and assigning sequences to base stations. Some embodiments may virtually eliminate interference between sensing transmissions, while accounting for the existence of only a limited set of orthogonal signals that can be used (which set of orthogonal signals may be much smaller than the set of network nodes that can cause interference to a base station or other network node which may be seeking to localize a target based on a desired sensing signal). The teachings of certain embodiments may improve the accuracy of environment sensing in an integrated sensing and communication system.

Description

INTERCELL INTERFERENCE COORDINATION FOR CELLULAR SENSINGCROSS REFERENCE TO RELATED INFORMATION

[0001] This application claims the benefit of United States of America priority application No. 63 / 635,321 filed on April 17, 2024 , titled “Intercell Interference Coordination for Cellular Sensing.”TECHNICAL FIELD

[0002] The present disclosure generally relates to systems and methods for environment sensing.BACKGROUND

[0003] Whereas both communication and sensing systems are well researched as separate topics, the integrated sensing and communication (ISAC) design concept is still in its infancy. See, e.g., Bayesteh et al., Integrated Sensing and Communication (ISAC) — From Concept to Practice, Huawei 6G Research Team, 2022 (available at https.Z / www. huawei.com / en / huaweit.ech / future-technologies / integrated-sensing- communication-concept-practice). However, even in this early stage of development, a variety of use cases have been identified. For example, one operating scenario for sensing in ISAC is bistatic sensing where one base station (BS) transmits a sensing signal while at least one other BS, typically on an adjacent site, is intended to receive the signal reflected from a target of interest.SUMMARY

[0004] One embodiment under the present disclosure comprises a method performed by a network node for environment sensing. The method includes: receiving one or more sensing signals, wherein: each sensing signal from the one or more sensing signals comprises a corresponding sequence; and the one or more sensing signals comprises a desired sensing signal from a transmitting network node of one or more local network nodes, wherein the corresponding sequence for the desired sensing signal is a known sequence; and identifying any sensing signals included in the one or more sensing signals other than the desired sensing signal as interfering sensing signals by performing one or more signal filtering acts. The one or more signal filtering acts comprises at least one of: identifying any first sensing signal of theone or more sensing signals whose corresponding sequence is the same as the known sequence but which is not from the one or more local network nodes as an interfering sensing signal; and identifying any second sensing signal of the one or more sensing signals whose corresponding sequence is different from the known sequence as an interfering sensing signal. The method further includes localizing a target of interest based on the desired sensing signal.

[0005] Another embodiment under the present disclosure includes a method performed by a network node for assigning sensing sequences to base stations. The method includes: identifying one or more base stations that are local to the network node; assigning a respective different corresponding sensing sequence to the network node and to each of the one or more base stations; and configuring the one or more base stations to transmit sensing signals including its corresponding sensing sequence.

[0006] Another embodiment under the present disclosure comprises a network node for environment sensing. The network node includes: processing circuitry and a memory. The memory contains instructions operable by the processing circuitry to: receive one or more sensing signals, wherein: each sensing signal from the one or more sensing signals comprises a corresponding sequence; and the one or more sensing signals comprises a desired sensing signal from a transmitting network node of one or more local network nodes, wherein the corresponding sequence for the desired sensing signal is a known sequence; and identify any sensing signals included in the one or more sensing signals other than the desired sensing signal as interfering sensing signals by performing one or more signal filtering acts. The one or more signal filtering acts comprises at least one of: identify any first sensing signal of the one or more sensing signals whose corresponding sequence is the same as the known sequence but which is not from the one or more local network nodes as an interfering sensing signal; and identify any second sensing signal of the one or more sensing signals whose corresponding sequence is different from the known sequence as an interfering sensing signal. The instructions are further operable by the processing circuitry to localize a target of interest based on the desired sensing signal.

[0007] Another embodiment under the present disclosure comprises a network node for assigning sensing sequences to base stations. The network node includes: processing circuitry and a memory. The memory contains instructions operable by the processing circuitry to: identify one or more base stations that are local to the network node; assign a respective different corresponding sensing sequence to the network node and to each of the one or morebase stations; and configure the one or more base stations to transmit sensing signals including its corresponding sensing sequence.

[0008] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an indication of the scope of the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] For a more complete understanding of the present disclosure, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0010] Fig. 1 illustrates a network scenario with Marco BSs and radar targets indicated as Reflection Points (RP);

[0011] Fig. 2 illustrates CDF of sensing SINR and SNR for a signal received from a Reflection Point (RP);

[0012] Fig. 3 illustrates a periodogram (delay -Doppler plane) with service range and signal received from remote transmitters;

[0013] Fig. 4 illustrates a frequency-time to Delay -Doppler plane transformation;

[0014] Fig. 5 illustrates a transformation from delay-Doppler to frequency-time plane;

[0015] Fig. 6 illustrates a method embodiment under the present disclosure;

[0016] Fig. 7 illustrates a method embodiment under the present disclosure;

[0017] Fig. 8 shows a schematic of a communication system embodiment under the present disclosure;

[0018] Fig. 9 shows a schematic of a user equipment embodiment under the present disclosure;

[0019] Fig. 10 shows a schematic of a network node embodiment under the present disclosure; and

[0020] Fig. 11 shows a schematic of a virtualization environment embodiment under the present disclosure.DETAILED DESCRIPTION

[0021] Before describing various embodiments of the present disclosure in detail, it is to be understood that this disclosure is not limited to the parameters of the particularlyexemplified systems, methods, apparatus, products, processes, and / or kits, which may, of course, vary. Thus, while certain embodiments of the present disclosure will be described in detail, with reference to specific configurations, parameters, components, elements, etc., the descriptions are illustrative and are not to be construed as limiting the scope of the claimed embodiments. In addition, the terminology used herein is for the purpose of describing the embodiments and is not necessarily intended to limit the scope of the claimed embodiments. Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0022] There currently exist certain challenges in the art identified above. In a cellular network, many BSs transmit at the same time, causing interference to the user equipment (UE) of other BSs. In classical cellular communications networks using time division duplex (TDD), all BSs are synchronized on a radio symbol, slot and frame level and either all transmit in a symbol or all receive in a symbol. However, for bistatic and multistatic sensing with at least 2 BS, it is required that one is transmitting in a symbol in which another BS receives. If another BS transmits in the same symbol an uncoordinated signal this can cause interference.

[0023] Figure 1 illustrates the network scenario with Macro BSs and radar targets modelled as scatter points and indicated as Reflection Points (RP), with the desired sensing signal paths and resulting interference paths when only 2 BS transmit sensing signals at the same time and 2 BS are configured to receive and evaluate the sensing signals at the same time.

[0024] The interference can be particularly strong for antennas mounted on roof tops where the antennas have Line of Sight (LOS) to each other, resulting in propagation conditions close to free space. The interference can be so strong that the estimates on the desired signal for sensing, e.g. range or Doppler frequency estimates, become unacceptably inaccurate.

[0025] Figure 2 shows the cumulative distribution function (CDF) of sensing signals received in such a scenario with RPs having a Radar Cross Section of 0 dBm2, for a hexagonal cellular network with 3-sectorized sites and inter-site-distance of 500m and randomly distributed RPs. The shown values are before exploiting processing gain over subcarriers and orthogonal frequency division multiplexing (OFDM) symbols. The signal to noise ratio (SNR) is sufficiently high to provide good sensing range and angle estimation accuracy, but due to the BS-BS interference the signal to interference and noise ratio (SINR) is 70dB lower, which would require aggregating over about 3000 OFDM symbols given a used bandwidth of100MHz with 3300 subcarriers, which implies a very high radio resource consumption, that in return would generate additional interference.

[0026] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. When there is a need for multiple BS to transmit a sensing symbol concurrently, because there are multiple targets, each one in the vicinity of a different bistatic BS pair, multiple BSs reuse the same transmit signal. Received direct signals from other BSs are then perceived like signals received from rather static objects. If there is interest only in moving objects, then the signals from other BSs can be suppressed by clutter suppression algorithms. Due to frequency offsets between BSs and phase noise, the signal from another BS will however appear to come from an object that has non-zero speed. The extent to which such BS signals can be suppressed depends on the frequency offsets, phase noise, and clutter suppression algorithm and will in general not be perfect.

[0027] Another approach is to use propagation delay to separate signals from targets from those received directly from other BSs. This may be achieved if only BSs that are sufficiently far apart reuse the same transmit signal. In some cases, if a closer BS reuses the same signal, the generated signal peak can be determined to be from another base station (based on known propagation time between base stations and high signal strength) and discarded, however, this approach may also interfere with detecting targets the same distance away.

[0028] In some cases, BS that are adjacent or close together may use signals that are separated in a parameter space (e.g., a one dimensional parameter space, like doppler space, or a two dimensional parameter space, like delay-doppler space), such that the signals can be separated at the receiver and thereby do not cause unresolvable interference. In this type of scenario, the BS network may thereby be divided into a signal reuse pattern as networks are on average deployed on a hexagonal grid. If N neighboring BSs use orthogonal signals this establishes a signal reuse-N pattern.

[0029] This document describes a scheme for allocating sensing signals to transmission points (e.g., base stations) in a cellular network such that mutual interference between BSs is mitigated. This scheme may be used to implement a method in a cellular network to associate different sequences to transmission points (TRPs) to mitigate mutual interference at any sensing receiver, characterized in that the TRPs are grouped into tiers and the TRPs within each tier are assigned sequences parameterized by a one dimensional or two dimensional parameter space such that the receiver can separate the transmission from different TRPs belonging to the same tier. In such a method, the parameter space may be a two dimensional parameter spacethat comprises any two of delay, doppler, code, and frequency domains, and the sequences may be separated by applying processing in the corresponding two dimensional domain. Using this type of scheme, various base stations may be able to receive sensing symbols during downlink time slots of a time division duplex connection.

[0030] These and other embodiments may provide one or more of the following technical advantages. Some embodiments may virtually eliminate interference between sensing transmissions, while accounting for the existence of only a limited set of orthogonal signals that can be used (which set of orthogonal signals may be much smaller than the set of network nodes that can cause interference to a base station or other network node which may be seeking to localize a target based on a desired sensing signal). The teachings of certain embodiments may improve the accuracy of environment sensing in an integrated sensing and communication system.

[0031] For sensing, signals with good autocorrelation in time domain may be transmitted. Zadoff-Chu sequences have perfect cyclic autocorrelation, i.e. it is non-zero only at a shift of zero and zero elsewhere. In sensing the receiver (RX) correlates the received signal with the known transmitted signal. In absence of noise, interference and signal windowing and when the propagation delays can only be integer multiples of the sample duration, the correlator output will be non-zero only at a sample time that is equal to the propagation time.

[0032] If a BS (BS1) receives a signal from an intended target and the same signal directly from a remote BS where the remote BS is separated by a minimum distance D then the signal from the remote BS does not raise the noise floor in the delay-Doppler periodogram of BS1, but both signals appear as distinct peaks.

[0033] Based on this disclosure, in some embodiments the peak from the remote BS is clearly identifiable as not coming from a nearby target. In a cellular network each BS is responsible only for targets in its vicinity, typically the target is closer to this BS than to other BSs, or more precisely the pathgain from the target to the BS is among the highest of the pathgains to all BSs. Such locations can be called the sensing cell area of an RX BS. This means that signals arriving with a propagation delay corresponding to locations further away than those in the sensing cell area can be ignored from the periodogram. The periodogram is thus evaluated for radar targets only over a service range that is limited by a set upper bound. Note that the sensing cell area may extend differently wide in different directions and the range of the periodogram - if it is determined as a function of angle of arrival - may vary across angle of arrivals.

[0034] Some embodiments feature reuse of the same sensing transmit signal only at BSs that are sufficiently far apart, so that the signal from a remote BS always arrives at BS1 with a delay above the service range. An example of this is illustrated in the periodogram (delay- doppler space) with service range and signal received from remote transmitters.

[0035] The signal from remote BSs will appear as a sharp peak in the periodogram only if the delay is still shorter than the cyclic repetition of the sequence in the transmit signal because propagation delays longer than the cyclic prefix (CP) cause intersymbol and inter(sub)carrier interference, which creates "leakage" in wider regions of the periodogram. In OFDM based communications, such a cyclic repetition is present in the form of the CP. For macrocell deployments where the BS-BS interference is most severe, typically numerologies with an OFDM symbol length of 66.6us or 33.3us are used with a CP of 4.7us and 2.35us, resp. The corresponding maximum propagation distance is therefore just 1410m and 705m, resp. BS-BS interference can, however, occur over longer distances than this. One approach to addressing this is to extend the cyclic repetition further. To do this in a way that is compatible with the new radio (NR) timing structure, typically the cyclic repetition is extended over an entire second OFDM symbol duration. With this the total cyclic repetition for the case of 33.3ps symbol length is 38ps, leading to a maximum propagation distance of 11400m, which can be regarded as sufficiently long to prevent strong interference. However, this approach may increase resource usage. A similar need for long cyclic repetitions is also present in Single- Frequency-Networks (SFNs) for broadcasting jointly from multiple BSs, and digital broadcasting networks are using very long OFDM symbols and CPs for that purpose.

[0036] For neighboring BSs of a considered BS, BS1, receiving a signal from an intended target, it cannot be ensured that the propagation distance between these two BSs is larger than the service range. To address this, some embodiments may use orthogonal signals for neighboring BS that are orthogonal also under the relatively small propagation delay with which they are received at BS1. Such signals would not raise the noise floor nor cause any peaks in the periodogram.

[0037] There are a variety of ways in which signals may be generated in embodiments implemented based on this disclosure. For example, in some cases, an auto-correlation-based code division multiplex (ACB CDM) may be used, where the method is to create the same signal at each neighboring BS and to create an artificial delay at the neighboring BSs, by applying a cyclic shift to the transmitted signal. As each BS in a neighborhood of BS can create interference to each other BS among the neighborhood, the BSs may have different cyclicshifts. Accordingly, in some embodiments, different base stations may be configured with different cyclic shifts of the same transmit signal. The transmit signal before applying the cyclic shift may be generated by creating a random sequence in the frequency domain. In some cases, this may be done with transmit signals which are Zadoff-Chu (ZC) sequences, as these also have the advantage to be Constant Amplitude Zero Auto Correlation (CAZAC) and cyclically shifted ZC sequences have zero autocorrelation as well.

[0038] In embodiments where it is present, the cyclic shift introduced at one transmitter may not coincide with the cyclic shift of a remote transmitter plus the propagation delay from that transmitter, in order to keep the separability of peaks at the RX-BS also in the presence of cyclic shifts in addition to the propagation delays. Therefore, the total interference free distance budget, e.g. the 11400m of the 2-symbol transmission introduced above, may be evenly split into the cyclic shifts described above.

[0039] As an example, consider BSs using omnidirectional antennas at each site in a regular hexagonal deployment. In this case, the signal reuse factor may be at least N=7. The cyclic shifts are then corresponding to a distance of 11400m / N*n, n=0,l,..N-l, where the shift step is 11400m / 7=1629m. This implies that when the propagation path of a served target is longer than these 1629m, then the signal from the target may be ignored by the serving BS, because it arrives after the first interfering BS's signal.

[0040] However, some embodiments may use an alternative approach. For example, in some cases, shorter shifts may be allowed. This may result in the signal from some of the other BSs creating interference peaks in the periodogram in the service range, but the position at which these peaks appear will be randomized. Because of this, the interference does not concentrate on a single range-Doppler point in the periodogram. This can be achieved by randomizing the cyclic shifts between transmitted pulses and / or introducing a constant phase shift between the sensing symbols transmitted by the same BS within a radar frame, where the phase shift may be different, e.g. randomized, across subcarriers.

[0041] The following way of calculating a periodogram which may be used in signal separation approaches such as described above is shown in Figure 4 :• Frequency -time plane: Transfer function per symbol occurrence (received signal after fast fourier transform (FFT) and frequency-domain matched filtering)• N horizontal FFTs across M symbols convert frequency-time plane into frequency- Doppler plane• M vertical inverse FFTs (IFFTs) across N subcarriers convert frequency -Doppler plane into delay-Doppler plane• Peaks in delay-Doppler plane correspond to identified targetsThis processing method explains the relation between both planes, frequency-time and delay- Doppler, and suggests that both dimensions can be exploited for interference mitigation.

[0042] To continue the previous example, if the service range is larger than the 1629m budget calculated above, then without randomization there would be a static interference from at least 1 BS at a delay between 1629m and the maximum service range. The interference would be static because the BS does not move, so the interference would be at the same delay on each OFDM symbol. If such static interference cannot be sufficiently cancelled, e.g., due to limited analog to digital conversion (ADC) resolution or digital signal processing precision, then it might be beneficial to use the above described randomization of (using different) cyclic transmit shifts such that the interference is on a different delay in each symbol. In this way, because a periodogram may be calculated over many symbols, if the interference is on a different delay in each symbol then in the periodogram it will be smeared out and thereby be distinguishable from sharper and stronger peaks of actual targets.

[0043] In some embodiments, the just described randomization methods may be applied within each radar frame (i.e., the frame consisting of the subcarriers and OFDM symbols used to calculate a periodogram). The effect is that the interference is distributed and thereby averaged over the delay and / or Doppler dimension unless it can be removed before calculating the periodogram by additional interference suppression techniques.

[0044] As another approach which may be used in some embodiments, randomization can be introduced only between radar frames, such that the transmit delay and Doppler are constant within a radar frame but randomized from frame to frame, with the effect that the interference peaks in the periodogram will be in different locations. This has the advantage that a location that is highly interfered in one radar frame and thereby radar targets cannot be detected in this location will with a high probability not be interfered in the next radar frame. The radar target parameters (delay, Doppler, or derived parameters like position and velocity) can then be inter- / extrapolated for the radar frames where the location of interest has been interfered.

[0045] Relatedly, in some embodiments, each BS may have a processing stage associating a weight to each sample in the delay domain and the weight may be lower the higher the interference is for the sample. The interference estimation can be e.g. based on the sample power, as interference received directly from another BS is typically much higher than signalsreflected from targets in the service range. An alternative is to signal the transmit shifts between the BSs and also the distance among BSs, so that each BS can calculate in which OFDM symbol interference will appear on which delay sample.

[0046] In embodiments using a weighting approach such as described in the preceding paragraph, the weights may be used to perform a weighted combination of the delay signal across OFDM symbols. Interference on a delay sample occurring only on a few OFDM symbols will thereby have a small impact on the combined delay estimate.

[0047] Another related approach which may be used in some embodiments is to apply Orthogonal Time Frequency Space (OTFS) precoding on the time-frequency grid shown in Figure 4 for generating the transmit signal (e.g., instead of using a ZC sequence and applying a cyclic shift within an OFDM symbol and potentially constant phase shifts between OFDM signals, such as described above). With OTFS, signals are originally created in the delay- Doppler domain and then transformed to the time-frequency domain by applying the inverse symplectic FFT (SFFT) as shown in Figure 5. On the RX side the inverse processing steps compared to those in Figure 5 are applied. The received signal in the delay Doppler domain is the convolution of the transmit signal and the channel, both in delay and Doppler domain. If the transmit signal in delay Doppler domain is a delta pulse, i.e. has only 1 non-zero element, then the received signal in the delay Doppler domain directly represents the channel, and thereby the delay and Doppler of the reflections from the radar targets, i.e. the periodogram . If the transmit signal in the delay-Doppler domain has multiple non-zero elements then the received signal in this domain has to be correlated with the transmit signal to obtain the periodogram. More generally, precoding can be implemented using 2D trigonometric transforms different from the SFFT, such as the two-dimensional Fast Fourier Transform, the two-dimensional Discrete Cosine Transform, or the Inverse (Discrete) Zak Transform.

[0048] Another way that some embodiments may increase the number of orthogonal signals available for sensing is to consider different sets of subcarriers for different signals. One possibility would be a first frequency portion to which a first set of sequences is mapped and a second frequency portion to which another set of sequences is mapped. Another possibility is to map the first set of sequences to a first subcarrier comb and the second set of sequences to a second subcarrier comb, e.g. even and odd subcarriers. Mapping such as used for the scheme used in Positioning Reference Symbols (PRS) in NR may also be used. Mapping a sequence to every second subcarrier creates a time-domain waveform which repeats itself within the OFDM symbol duration. When using simple receivers, this can create ambiguity fortargets that have a time of flight larger than half an OFDM symbol duration; with 15 kHz subcarrier spacing this would correspond to 4950 m. However, the reuse 7 from previous example limits the cell sensing range to 1629 m, so 4950 m does not impose any additional restriction. Even combs with comb distances larger than 2 can be considered, a comb distance n leads to n repetitions within an OFDM symbol duration. For example, a comb 5 would remain unambiguous for target time of flights less than 1 / 5 of the OFDM symbol duration, which would for 15kHz subcarrier spacing correspond to targets with a propagation distance of up to 1980 m, larger than 1629 m and thus not creating any additional limitations. The comb structure has the nice property that it does maintain the same total bandwidth and by that does not reduce the range resolution.

[0049] Another approach which may be used in some embodiments, such as embodiments in which not enough orthogonal comb signals exist in the frequency domain, e.g. in the above example if more than 5 orthogonal signal are required, is to use a scheme of non-equidistant subcarrier allocation. In order to avoid the artefacts arising when calculating FFT based periodograms based on an incomplete (e.g., missing subcarriers to form an equidistant set of subcarriers that are required for FFT to avoid artefacts) set of subcarriers and / or OFDM symbols, methods of Compressed Sensing (CS) may be employed. The reconstruction of the periodogram from the incomplete set of subcarriers and / or symbols may be supported by ensuring that the density of radar targets in the delay -Doppler plane is sparse, which is typically the case.

[0050] In some embodiments, randomization can be coordinated between transmitters (TXs), as described in the following pseudocode that allocates Nst subcarriers to each TX (k) in a set Sk, where no subcarrier is allocated to more than 1 TX:So={l:Nsc} % set of all subcarriersNst=fl oor(Nsc / Ntx) for k=l:NtxSk=randperm(So,Nst); % i.e. select Nst subcarriers from So at randomSo=So \ Sk % remove set Sk from So

[0051] In some embodiments, the configuration of the sensing signal for each TX BS and RX BS can be done via proprietary signalling. It is also possible that signalling may be standardized. The configuration of the sensing signal for each TX BS could be long term, changing only when e.g. BSs are added or removed the network. Since for a TX-BS different RX-BSs may be selected depending on the target position, the RX-BS, in the sensing signallingproviding the information which time, frequency and beam resources to use for sensing reception, also needs to be informed about which TX signal to correlate with. Since the selected target can change dynamically, the configuration of the RX-BS also needs to be changed dynamically.

[0052] It should be understood that, while this description did not address noise, and focused on interference, signal windowing and propagation delays being integer multiples of the sample duration, this is done simply for simplicity, and does not imply limitations on potential embodiments. Instead, the disclosed technology could be applied in other contexts as well. For example, while the simplifying treatment in this description result in perfect peaks, in a realistic situation, noise and / or other confounding factors will lead to sidelobes in the autocorrelation, and embodiments of the disclosed technology may include features to address this, such as through windowing across subcarriers at the transmitter or receiver to obtain sidelobe suppression. Other approaches may also be applied in various embodiments to address issues which may be encountered in particular situations.

[0053] To further illustrate potential approaches which may be taken in implementing aspects of the disclosed technology, Figure 6 illustrates a method 600 which may be performed by a network node 3300 for environment sensing. Step 610 is receiving one or more sensing signals, wherein: each sensing signal from the one or more sensing signals comprises a corresponding sequence; and the one or more sensing signals comprises a desired sensing signal from a transmitting network node of one or more local network nodes, wherein the corresponding sequence for the desired sensing signal is a known sequence. Step 620 is identifying any sensing signals included in the one or more sensing signals other than the desired sensing signal as interfering sensing signals by performing one or more signal filtering acts. The one or more signal filtering acts comprises at least one of: step 630, identifying any first sensing signal of the one or more sensing signals whose corresponding sequence is the same as the known sequence but which is not from the one or more local network nodes as an interfering sensing signal; and step 640 identifying any second sensing signal of the one or more sensing signals whose corresponding sequence is different from the known sequence as an interfering sensing signal. Step 650 is localizing a target of interest based on the desired sensing signal.

[0054] Method 600 can comprise a variety of additional, alternative, and / or optional steps. For example, in some variations localizing the target of interest based on the desired sensing signal comprises determining a location for the target of interest. In certain embodiments, theknown sequence comprised in the desired sensing signal may be a Zadoff-Chu sequence. In certain embodiments, for any network node of the one or more local network nodes, a propagation delay of signals between that network node and the network node performing the method may be less than a set upper bound propagation delay. In certain embodiments, for any network node of the one or more local network nodes, that network node is local to the network node performing the method in that it is within a sensing cell area of the network node performing the method, such that an interfering sensing signal transmitted by that network node may arrive at the network node performing the method before any desired sensing signal from within the sensing cell area, e.g. a desired sensing signal arriving from a target within the sensing cell area. In certain variations, for any network node of the one or more local network nodes, that network node is local to the network node performing the method in that a sensing signal, which may be an interfering sensing signal, transmitted by that network node may arrive at the network node performing the method before any desired sensing signal from the sensing cell area of the network node performing the method. In other examples, in certain embodiments, for any network node of the one or more local network nodes, that network node is local to the network node performing the method in that it is a neighboring network node for the network node performing the method. In certain variations, any of the network node performing the method and any network node of the one or more local network nodes is a base station. In certain cases, the known sequence comprised in the desired sensing signal has a length of 33ps plus 38ps. In certain cases, for any second sensing signal from the one or more local network nodes, the corresponding sequence for that signal is orthogonal in a parameter space both to the known sequence comprised in the desired sensing signal and to the sequence comprised in any other interfering sensing signal from the one or more local network nodes. In certain embodiments, the parameter space has at least two dimensions, wherein each dimension of the parameter space is selected from one or more of: delay; doppler; code; range; time slot; and frequency. In certain cases, the identifying any first sensing signal included in the one or more sensing signals whose corresponding sequence is the same as the known sequence but which is not from the one or more local network nodes as an interfering sensing signal is performed by identifying signals associated with peaks in a parameter space periodogram which are higher than a peak in the parameter space periodogram associated with the desired sensing signal as interfering sensing signals. In certain variations, for a sensing signal of the one or more sensing signals, its corresponding sequence is transmitted over a plurality of pulses, each of which is shifted by at least one of: a different shift; or a constant shift; withrespect to at least one of: delay between pulses; and / or phase across subcarriers. In certain embodiments, the desired sensing signal is, or has been, transformed from a delay-doppler domain signal to a time-frequency domain signal. The desired sensing signal may e.g. have been transformed from a delay-doppler domain signal to a time-frequency domain signal by the transmitting network node prior to being transmitted. Generally, for any sensing signal of the one or more sensing signals, that sensing signal may be, or have been, transformed from a delay-doppler domain signal to a time-frequency domain signal before being transmitted. In certain variations, receiving the one or more sensing signals comprises receiving the one or more sensing signals during one or more downlink time slots of a TDD communication link. In certain cases, each sensing signal from the one or more sensing signals further comprises a corresponding cyclic shift. Some embodiments may comprise a network node for environment sensing, the network node comprising: processing circuitry configured to perform any of the steps of any of the preceding embodiments; and power supply circuitry configured to supply power to the processing circuitry.

[0055] Another method which may be implemented based on this disclosure is shown in Figure 7. Figure 7 shows a method 700 performed by a network node for assigning sensing sequences to base stations3300 . Step 710 is identifying one or more base stations 3300 that are local to the network node. Step 720 is assigning a respective different corresponding sensing sequence to the network node and to each of the one or more base stations. This may comprise, e.g., that the network node and each of the one or more base stations may be assigned respective sensing sequences, where the sensing sequences are different to each other and each sensing sequence corresponds to a respective one of the one or more base stations and the network node. Step 730 is configuring the one or more base stations to transmit sensing signals including its corresponding sensing sequence.

[0056] Method 700 can comprise a variety of additional, alternative, and / or optional steps. For example, in some variations, for at least one of the one or more base stations, the corresponding sensing sequence may be a Zadoff-Chu sequence. In certain embodiments, for any base station of the one or more base stations, a propagation delay of signals between the base station and the network node may be less than a set upper bound propagation delay. In certain embodiments, for any base station of the one or more base stations, the corresponding sequence assigned to the base station has a length of 33ps plus 38ps. In certain cases, for a first base station of the one or more base stations, a first corresponding sensing sequence assigned to the first base station is orthogonal in a parameter space to a second corresponding sensingsequence assigned to a second base station of the one or more base stations. In certain variations, the parameter space has at least two dimensions, wherein each dimension of the parameter space is selected from one or more of: delay; doppler; code; range; time slots; and frequency. Some embodiments may comprise a network node for assigning sensing sequences to base stations, the network node comprising: processing circuitry configured to perform any of the steps of any of the preceding embodiments; and power supply circuitry configured to supply power to the processing circuitry.

[0057] Figure 8 shows an example of a communication system 3100 in accordance with some embodiments. In the example, the communication system 3100 includes a telecommunication network 3102 that includes an access network 3104, such as a radio access network (RAN), and a core network 3106, which includes one or more core network nodes 3108. The access network 3104 includes one or more access network nodes, such as network nodes 3110a and 3110b (one or more of which may be generally referred to as network nodes 3110), or any other similar 3rd Generation Partnership Project (3GPP) access points or non- 3 GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 3102 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 3102 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 3102, including one or more network nodes 3110 and / or core network nodes 3108.

[0058] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O- CU-CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN accessnode may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an 0-2 interface defined by the 0-RAN Alliance or comparable technologies. The network nodes 3110 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 3112a, 3112b, 3112c, and 3112d (one or more of which may be generally referred to as UEs 3112) to the core network 3106 over one or more wireless connections.

[0059] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 3100 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 3100 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0060] The UEs 3112 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 3110 and other communication devices. Similarly, the network nodes 3110 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 3112 and / or with other network nodes or equipment in the telecommunication network 3102 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 3102.

[0061] In the depicted example, the core network 3106 connects the network nodes 3110 to one or more host computing systems, such as host 3116. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 3106 includes one more core network nodes (e.g., core network node 3108) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 3108. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), MobilityManagement Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0062] The host 3116 may be under the ownership or control of a service provider other than an operator or provider of the access network 3104 and / or the telecommunication network 3102. The host 3116 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0063] As a whole, the communication system 3100 of Figure 8 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0064] In some examples, the telecommunication network 3102 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 3102 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 3102. For example, the telecommunications network 3102 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC)ZMassive loT services to yet further UEs.

[0065] In some examples, the UEs 3112 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmitinformation to the access network 3104 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 3104. Additionally, a UE may be configured for operating in single- or multi-RAT or multi -standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN- DC).

[0066] In the example, the hub 3114 communicates with the access network 3104 to facilitate indirect communication between one or more UEs (e.g., UE 3112c and / or 3112d) and network nodes (e.g., network node 3110b). In some examples, the hub 3114 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 3114 may be a broadband router enabling access to the core network 3106 for the UEs. As another example, the hub 3114 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 3110, or by executable code, script, process, or other instructions in the hub 3114. As another example, the hub 3114 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 3114 may be a content source. For example, for a UE that is a VR device, display, loudspeaker, or other media delivery device, the hub 3114 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 3114 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 3114 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0067] The hub 3114 may have a constant / persistent or intermittent connection to the network node 3110b. The hub 3114 may also allow for a different communication scheme and / or schedule between the hub 3114 and UEs (e.g., UE 3112c and / or 3112d), and between the hub 3114 and the core network 3106. In other examples, the hub 3114 is connected to the core network 3106 and / or one or more UEs via a wired connection. Moreover, the hub 3114 may be configured to connect to an M2M service provider over the access network 3104 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes via a wired or wireless connection 3110 while still connected via the hub 3114. In some embodiments, the hub 3114 may be a dedicated hub -that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 3110b. In other embodiments, the hub 3114 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 3110b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0068] Figure 9 shows a UE 3200 in accordance with some embodiments. The UE 3200 presents additional details of some embodiments of the UE 3112 of Figure 8. As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage / playback device, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), an Augmented Reality (AR) or Virtual Reality (VR) device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3 GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0069] A UE may support device-to-device (D2D) communication, for example by implementing a 3 GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle- to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0070] The UE 3200 includes processing circuitry 3202 that is operatively coupled via a bus 3204 to an input / output interface 3206, a power source 3208, a memory 3210, a communication interface 3212, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 9. The level of integration between the components may vary from one UE to another UE. Further, certainUEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0071] The processing circuitry 3202 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 3210. The processing circuitry 3202 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 3202 may include multiple central processing units (CPUs).

[0072] In the example, the input / output interface 3206 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 3200. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0073] In some embodiments, the power source 3208 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 3208 may further include power circuitry for delivering power from the power source 3208 itself, and / or an external power source, to the various parts of the UE 3200 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 3208. Power circuitry may perform any formatting, converting, or othermodification to the power from the power source 3208 to make the power suitable for the respective components of the UE 3200 to which power is supplied.

[0074] The memory 3210 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 3210 includes one or more application programs 3214, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 3216. The memory 3210 may store, for use by the UE 3200, any of a variety of various operating systems or combinations of operating systems.

[0075] The memory 3210 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD- DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 3210 may allow the UE 3200 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 3210, which may be or comprise a device-readable storage medium.

[0076] The processing circuitry 3202 may be configured to communicate with an access network or other network using the communication interface 3212. The communication interface 3212 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 3222. The communication interface 3212 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 3218 and / ora receiver 3220 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 3218 and receiver 3220 may be coupled to one or more antennas (e.g., antenna 3222) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0077] In the illustrated embodiment, communication functions of the communication interface 3212 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / intemet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0078] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 3212, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0079] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0080] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examplesof such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 3200 shown in Figure 9.

[0081] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3 GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0082] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’ s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0083] Figure 10 shows a network node 3300 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to,access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)), O-RAN nodes or components of an O-RAN node (e.g, O-RU, O-DU, O-CU).

[0084] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g, in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0085] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi -standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g. Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0086] The network node 3300 includes a processing circuitry 3302, a memory 3304, a communication interface 3306, and a power source 3308. The network node 3300 may be composed of multiple physically separate components (e.g, a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 3300 comprises multiple separate components (e.g, BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 3300 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g, separate memory 3304 for different RATs) and some components may be reused (e.g, a same antenna 3310 may be shared by different RATs). The network node 3300 may also include multiple sets of the variousillustrated components for different wireless technologies integrated into network node 3300, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 3300.

[0087] The processing circuitry 3302 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 3300 components, such as the memory 3304, to provide network node 3300 functionality.

[0088] In some embodiments, the processing circuitry 3302 includes a system on a chip (SOC). In some embodiments, the processing circuitry 3302 includes one or more of radio frequency (RF) transceiver circuitry 3312 and baseband processing circuitry 3314. In some embodiments, the radio frequency (RF) transceiver circuitry 3312 and the baseband processing circuitry 3314 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 3312 and baseband processing circuitry 3314 may be on the same chip or set of chips, boards, or units.

[0089] The memory 3304 may comprise any form of volatile or non-volatile computer- readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computerexecutable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 3302. The memory 3304 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 3302 and utilized by the network node 3300. The memory 3304 may be used to store any calculations made by the processing circuitry 3302 and / or any data received via the communication interface 3306. In some embodiments, the processing circuitry 3302 and memory 3304 is integrated.

[0090] The communication interface 3306 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 3306 comprises port(s) / terminal(s) 3316 to send and receive data, for example to and from a network over a wired connection. The communication interface 3306 also includes radio front-end circuitry 3318 that may be coupled to, or in certain embodiments a part of, the antenna 3310. Radio front-end circuitry 3318 comprises filters 3320 and amplifiers 3322. The radio front-end circuitry 3318 may be connected to an antenna 3310 and processing circuitry 3302. The radio front-end circuitry may be configured to condition signals communicated between antenna 3310 and processing circuitry 3302. The radio front-end circuitry 3318 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 3318 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 3320 and / or amplifiers 3322. The radio signal may then be transmitted via the antenna 3310. Similarly, when receiving data, the antenna 3310 may collect radio signals which are then converted into digital data by the radio front-end circuitry 3318. The digital data may be passed to the processing circuitry 3302. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0091] In certain alternative embodiments, the network node 3300 does not include separate radio front-end circuitry 3318, instead, the processing circuitry 3302 includes radio front-end circuitry and is connected to the antenna 3310. Similarly, in some embodiments, all or some of the RF transceiver circuitry 3312 is part of the communication interface 3306. In still other embodiments, the communication interface 3306 includes one or more ports or terminals 3316, the radio front-end circuitry 3318, and the RF transceiver circuitry 3312, as part of a radio unit (not shown), and the communication interface 3306 communicates with the baseband processing circuitry 3314, which is part of a digital unit (not shown).

[0092] The antenna 3310 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 3310 may be coupled to the radio frontend circuitry 3318 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 3310 is separate from the network node 3300 and connectable to the network node 3300 through an interface or port.

[0093] The antenna 3310, communication interface 3306, and / or the processing circuitry 3302 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, dataand / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 3310, the communication interface 3306, and / or the processing circuitry 3302 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0094] The power source 3308 provides power to the various components of network node3300 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 3308 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 3300 with power for performing the functionality described herein. For example, the network node 3300 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 3308. As a further example, the power source 3308 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0095] Embodiments of the network node 3300 may include additional components beyond those shown in Figure 10 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 3300 may include user interface equipment to allow input of information into the network node 3300 and to allow output of information from the network node 3300. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 3300. In some embodiments providing a core network node, such as core network node 3108 of Figure 8 some components, such as the radio front-end circuitry 3318 and the RF transceiver circuitry 3312 may be omitted.

[0096] Figure 11 is a block diagram illustrating a virtualization environment 3400 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implementedas virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 3400 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 3400 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an 0-2 interface. Virtualization may facilitate distributed implementations of a network node, UE, core network node, or host.

[0097] Applications 3402 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 3400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0098] Hardware 3404 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 3406 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 3408a and 3408b (one or more of which may be generally referred to as VMs 3408), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 3406 may present a virtual operating platform that appears like networking hardware to the VMs 3408.

[0099] The VMs 3408 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 3406. Different embodiments of the instance of a virtual appliance 3402 may be implemented on one or more of VMs 3408, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0100] In the context of NFV, a VM 3408 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 3408, and that part of hardware 3404 that executes that VM, be it hardwarededicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 3408 on top of the hardware 3404 and corresponds to the application 3402.

[0101] Hardware 3404 may be implemented in a standalone network node with generic or specific components. Hardware 3404 may implement some functions via virtualization. Alternatively, hardware 3404 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 3410, which, among others, oversees lifecycle management of applications 3402. In some embodiments, hardware 3404 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 3412 which may alternatively be used for communication between hardware nodes and radio units.

[0102] Although the computing devices described herein (e.g., UEs, network nodes) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of anyof such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0103] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer- readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.Example Embodiments

[0104] Below are provided various possible, but non-limiting, examples of possible embodiments under the present disclosure.Group A Embodiments

[0105] 1. A method performed by a network node for environment sensing, the method comprising: receiving a set of sensing signals, wherein:• each sensing signal from the set of sensing signals comprises a corresponding sequence; and• the set of sensing signals comprises a desired sensing signal from a transmitting network node included in a set of local network nodes, wherein corresponding sequence for the desired sensing signal is a known sequence; identifying sensing signals included in the set of sensing signals other than the desired sensing signal as interfering sensing signals by performing a set of signal filtering acts, wherein the set of signal filtering acts comprises:• identifying a first sensing signal included in the set of sensing signals whose corresponding sequence is the same as the known sequence transmitted by the desired sensing signal and which is not from the set of local network nodes as interfering; and• identifying a second sensing signal included in the set of sensing signals whose corresponding sequence is different from the known sequence transmitted by the desired sensing signal as interfering; and localizing a target of interest based on the desired sensing signal.

[0106] 2 The method of embodiment 1, wherein localizing the target of interest based on the desired sensing signal comprises determining a location for the target of interest.

[0107] 3. The method of any one of embodiments 1-2, wherein the known sequence transmitted by the desired sending signal is a Zadoff-Chu sequence.

[0108] 4. The method of any one of embodiments 1-3, wherein, for a network node in the set of local network nodes, a propagation delay between that network node and the network node performing the method is less than a set upper bound propagation delay.

[0109] 5. The method of any one of embodiments 1-4, wherein, for a network node in the set of local network nodes, that network node is within a sensing cell area of the network node performing the method.

[0110] 6. The method of any one of embodiments 1-5, wherein, for a network node in the set of local network nodes, that network node is a neighboring network node for the network node performing the method.

[0111] 7 The method of any one of embodiments 1-6, wherein any of the network node performing the method and any network node from the set of local network nodes is a base station.

[0112] 8. The method of any one of embodiments 1-7, wherein the known sequence transmitted by the desired sensing signal has a length of at least 38ps.

[0113] 9. The method of any one of embodiments 1-8, wherein, for any interfering sensing signal from the set of local network nodes, the corresponding sequence for that signal is orthogonal in a parameter space both to the known sequence transmitted by the desired sensing signal and to the sequence transmitted by any other interfering sensing signal from the set of local network nodes.

[0114] 10. The method of embodiment 9, wherein the parameter space has at least two dimensions, wherein each dimension of the parameter space is selected from one or more of: delay; doppler; code; range; time slot; and frequency.

[0115] 11. The method of any one of embodiments 9-10, wherein identifying a sensing signal included in the set of sensing signals which transmits the sequence which is the same as the known sequence transmitted by the desired sensing signal and which is not from the set oflocal network nodes as interfering is performed by identifying signals associated with peaks in a parameter space periodogram which are higher than a peak in the parameter space periodogram associated with the desired sensing signal as interfering sensing signals.

[0116] 12. The method of embodiment 11, wherein, for a sensing signal in the set of sensing signals its corresponding sequence is transmitted over a plurality of pulses, each of which is shifted by a different shift with respect to: delay between pulses; and / or phase across subcarriers.

[0117] 13. The method of embodiment 11, wherein the set of signal filtering acts comprises, on the transmitter side, for a signal from the set of sensing signals, transforming that sensing signal from a delay-doppler domain signal to a time-frequency domain signal.

[0118] 14. The method of any one of embodiments 1-13. wherein receiving the set of sensing signals comprises receiving the set of sensing signals during one or more downlink time slots of a time division duplex (TDD) communication link.Group B Embodiments

[0119] 15. A network node for environment sensing, the network node comprising: processing circuitry configured to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the processing circuitry.Group C Embodiments

[0120] 16. A method performed by a host computing system for allocating sensing sequences among a plurality of network nodes, the method comprising, for each network node of the plurality of network nodes: identifying a set of local network nodes for that network node; assigning a different corresponding sensing sequence to that network node and to each network node in the set of local network nodes for that network node; and configuring that network node to transmit sensing signals including its corresponding sensing sequence.

[0121] 17. The method of embodiment 16, wherein the plurality of network nodes include a plurality of base stations.

[0122] 18. The method of any one of embodiments 16-17, wherein, for a network node from the plurality of network nodes, the sensing sequence assigned to that network node is a Zadoff-Chu sequence.

[0123] 19. The method of any one of embodiments 16-18, wherein, for a network node in the plurality of network nodes, for a local network node in set of local network nodes identified for that network node, a propagation delay between that network node and that local network node is less than a set upper bound propagation delay.

[0124] 20. The method of any one of embodiments 16-19, wherein, for a network node in the plurality of network nodes, the set of local network nodes identified for that network node are within a sensing cell area of that network node.

[0125] 21. The method of any one of embodiments 16-20, wherein, for each network node in the plurality of network nodes, for each local network node in set of local network nodes identified for that network node, that local network node is a neighboring network node for that network node.

[0126] 22. The method of any one of embodiments 16-21, wherein, for a network node in the plurality of network nodes, the corresponding sequence assigned to that network node has a length at least 38ps.

[0127] 23. The method of any one of embodiments 16-22, wherein, for a network node in the plurality of network nodes, the corresponding sequence assigned to that network node is orthogonal in a parameter space to a corresponding sequence assigned to a local network node in the set of local network nodes assigned to that network node.

[0128] 24. The method of embodiment 23, wherein the parameter space has at least two dimensions, wherein each dimension of the parameter space is selected from one or more of: delay; doppler; code; range; time slots; and frequency.Group D Embodiments

[0129] 25. A host system for allocating sensing sequences, the host system comprising: processing circuitry configured to perform any of the steps of any of the Group C embodiments; and power supply circuitry configured to supply power to the processing circuitry.

Claims

CLAIMSWhat is claimed is:

1. A method (600) performed by a network node (3300) for environment sensing, the method comprising: receiving (610) one or more sensing signals, wherein: each sensing signal from the one or more sensing signals comprises a corresponding sequence; and the one or more sensing signals comprises a desired sensing signal from a transmitting network node of one or more local network nodes, wherein the corresponding sequence for the desired sensing signal is a known sequence; identifying (620) any sensing signals included in the one or more sensing signals other than the desired sensing signal as interfering sensing signals by performing one or more signal filtering acts, wherein the one or more signal filtering acts comprises at least one of: identifying (630) any first sensing signal of the one or more sensing signals whose corresponding sequence is the same as the known sequence but which is not from the one or more local network nodes as an interfering sensing signal; and identifying (640) any second sensing signal of the one or more sensing signals whose corresponding sequence is different from the known sequence as an interfering sensing signal; and localizing (650) a target of interest based on the desired sensing signal.

2. The method of claim 1, wherein localizing the target of interest based on the desired sensing signal comprises determining a location for the target of interest.

3. The method of any of claims 1 to 2, wherein the known sequence comprised in the desired sensing signal is a Zadoff-Chu sequence.

4. The method of any of claims 1 to 3, wherein, for any network node of the one or more local network nodes, a propagation delay of signals between that network node and the network node performing the method is less than a set upper bound propagation delay.

5. The method of any of claims 1 to 4, wherein, for any network node of the one or more local network nodes, that network node is local to the network node performing the method in that it is within a sensing cell area of the network node performing the method, such that an interfering sensing signal transmitted by that network node may arrive at the network node performing the method before any desired sensing signal transmitted by another network node located within the sensing cell area.

6. The method of any of claims 1 to 5, wherein, for any network node of the one or more local network nodes, that network node is local to the network node performing the method in that it is a neighboring network node for the network node performing the method.

7. The method of any of claims 1 to 6, wherein any of the network node performing the method and any network node of the one or more local network nodes is a base station.

8. The method of any of claims 1 to 7, wherein the known sequence comprised in the desired sensing signal has a length of 33ps plus 38ps.

9. The method of any of claims 1 to 8, wherein, for any second sensing signal from the one or more local network nodes, the corresponding sequence for that signal is orthogonal in a parameter space both to the known sequence comprised in the desired sensing signal and to the sequence comprised in any other interfering sensing signal from the one or more local network nodes.

10. The method of claim 9, wherein the parameter space has at least two dimensions, wherein each dimension of the parameter space is selected from one or more of: delay; doppler; code; range; time slot; and frequency.

11. The method of any of claims 9 to 10, wherein the identifying any first sensing signal of the one or more sensing signals whose corresponding sequence is the same as the known sequence but which is not from the one or more local network nodes as an interfering sensing signal is performed by identifying signals associated with peaks in a parameter space periodogram which are higher than a peak in the parameter space periodogram associated with the desired sensing signal as interfering sensing signals.

12. The method of claim 11, wherein, for a sensing signal of the one or more sensing signals, its corresponding sequence is transmitted over a plurality of pulses, each of which is shifted by at least one of: a different shift; or a constant shift; with respect to at least one of: delay between pulses; and / or phase across subcarriers.

13. The method of claim 11, wherein the desired sensing signal is transformed from a delay - doppler domain signal to a time-frequency domain signal.

14. The method of any of claims 1 to 13, wherein receiving the one or more sensing signals comprises receiving the one or more sensing signals during one or more downlink time slots of a time division duplex, TDD, communication link.

15. The method of any of claims 1 to 14, wherein each sensing signal from the one or more sensing signals further comprises a corresponding cyclic shift.

16. A method (700) performed by a network node (3300) for assigning sensing sequences to base stations, the method comprising: identifying (710) one or more base stations (3300) that are local to the network node; assigning (720) a respective different corresponding sensing sequence to the network node and to each of the one or more base stations; and configuring (730) the one or more base stations to transmit sensing signals including its corresponding sensing sequence.

17. The method of claim 16, wherein, for at least one of the one or more base stations, the corresponding sensing sequence is a Zadoff-Chu sequence.

18. The method of claim 16 or 17, wherein, for any base station of the one or more base stations, a propagation delay of signals between the base station and the network node is less than a set upper bound propagation delay.

19. The method of any of claims 16 to 18, wherein, for any base station of the one or more base stations, the corresponding sequence assigned to the base station has a length of 33 ps plus20. The method of any of claims 16 to 19, wherein, for a first base station of the one or more base stations, a first corresponding sensing sequence assigned to the first base station is orthogonal in a parameter space to a second corresponding sensing sequence assigned to a second base station of the one or more base stations.

21. The method of claim 20, wherein the parameter space has at least two dimensions, wherein each dimension of the parameter space is selected from one or more of: delay; doppler; code; range; time slots; and frequency.

22. A network node (3300) for environment sensing, the network node comprising: processing circuitry (3302); and a memory (3304) storing instructions whereby the processing circuitry is operable to: receive one or more sensing signals, wherein: each sensing signal from the one or more sensing signals comprises a corresponding sequence; and the one or more sensing signals comprises a desired sensing signal from a transmitting network node of one or more local network nodes, wherein the corresponding sequence for the desired sensing signal is a known sequence; identify any sensing signals included in the one or more sensing signals other than the desired sensing signal as interfering sensing signals by performing one or more signal filtering acts, wherein the one or more signal filtering acts comprises at least one of: identify any first sensing signal of the one or more sensing signals whose corresponding sequence is the same as the known sequence but which is not from the one or more local network nodes as an interfering sensing signal; and identify any second sensing signal of the one or more sensing signals whose corresponding sequence is different from the known sequence as an interfering sensing signal; and localize a target of interest based on the desired sensing signal.

23. A network node (3300) for assigning sensing sequences to base stations (3300), the network node comprising:processing circuitry (3302); and a memory (3308) storing instructions whereby the processing circuitry is operable to: identify one or more base stations that are local to the network node; assign a respective different corresponding sensing sequence to the network node and to each of the one or more base stations; and configure the one or more base stations to transmit sensing signals including its corresponding sensing sequence.

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