Patent Application
20250119336
Embodiments of invention relates to a first communication device and a second communication device for probabilistic constellation shaping modulation in a communication system. Furthermore, the invention also relates to corresponding methods and a computer program.
Modern communication systems, such as 3GPP 5G New Radio (NR), have evolved into the age of very high modulation order such as 1024-quadrature amplitude modulation (QAM) and 4096-QAM, in order to achieve a high throughput and approach the Shannon capacity in high signal-to-noise (SNR) regime. However, it is known that attaining the Shannon capacity requires the transmitted signal to be Gaussian. In the high SNR regime, the capacity of equiprobable QAM or PAM (pulse amplitude modulation) symbols asymptotically approaches a straight line parallel to the Shannon capacity and shows an SNR loss of 1.53 dB. Therefore, transmitting with equiprobable symbols is not enough, and probabilistic constellation shaping (PCS) which produces a Gaussian-like constellation is a promising method to reduce the gap to the Shannon capacity.
An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.
Another objective of embodiments of the invention is to provide a modulation scheme which exploits higher throughput compared to conventional solutions.
The above and further objectives are solved by the subject matter of the independent claims. Further embodiments of the invention can be found in the dependent claims.
According to a first aspect of the invention, the above mentioned and other objectives are achieved with a first communication device for a communication system, the first communication device being configured to:
An advantage of the first communication device according to the first aspect is that the mapping of the four sets of information bits is performed in parallel, and is fully compatible with existing communication systems by providing the binary bits after de-mapping as so-called ‘new’ information bit for processing at the first communication device. The existing communication systems may be 3GPP NR but is not limited thereto.
In an implementation form of a first communication device according to the first aspect, the predetermined probability distribution function determines the occurrence of each amplitude in the first number of modulated symbols and in the second number of modulated symbols, respectively, from M number of predefined positive amplitudes.
In an implementation form of a first communication device according to the first aspect, the M number of predefined positive amplitudes are obtained from a pulse amplitude modulation.
The positive amplitudes from a pulse amplitude modulation may comprise symbols {1·√{square root over (β)}, 3·√{square root over (β)}, . . . , (2M−1)·√{square root over (β)}}, where β is a normalization factor and can be set to e.g.,
such that the average power of all positive amplitudes is 1.
In an implementation form of a first communication device according to the first aspect, the predetermined probability distribution function is a Gaussian or a near Gaussian probability distribution function.
An advantage with this implementation form is that to attain a given entropy, the Gaussian alphabet yields the least average-power of the constellation symbols compared to other symbol distributions. This means that transmit power can be increased proportional to the average-power decrement with the probabilistic constellation shaping, while the effective average transmit-power of the symbols remains unchanged. This means that the throughput can be increased in the communication system.
In an implementation form of a first communication device according to the first aspect, the mapping of the second set of information bits and the fourth set of information bits comprises map an information bit 0 to a sign bit 1 and an information bit 1 to a sign bit −1, or vice versa.
In an implementation form of a first communication device according to the first aspect, the set of complex-valued modulated symbols are quadrature amplitude modulated symbols.
In an implementation form of a first communication device according to the first aspect, the first communication device being configured
An advantage with this implementation form is that these processing steps are the same as in some existing communication system thereby providing full backwards compatibility with such communication systems.
In an implementation form of a first communication device according to the first aspect, the de-mapping of the set of complex-valued modulated symbols comprises an inverse operation to the mapping of the encoded bits.
In an implementation form of a first communication device according to the first aspect, the first communication device being configured
An advantage with this implementation form is that the control signaling can be performed with low overhead.
In an implementation form of a first communication device according to the first aspect, the predetermined probability density function is represented as a Gaussian distribution.
An advantage with this implementation form is that the Gaussian distribution can be represented by a single parameter which can be signaled to the second communication device.
In an implementation form of a first communication device according to the first aspect, the first communication device being configured
An advantage with this implementation form is that the control signaling can be performed with low overhead.
In an implementation form of a first communication device according to the first aspect, the first communication device being configured
An advantage with this implementation form is that the signaling overhead can be kept at a minimum, and the predetermined probability distribution function or the occurrences of all positive amplitudes can be given by a modulation and coding scheme table that is known to both the first and the second communication devices.
In an implementation form of a first communication device according to the first aspect, the modulating of the first set of information bits and the third set of information bits comprises
An advantage with this implementation form is that the processing of a large number of information bits may be performed in parallel thereby reducing implementation complexity and decreasing processing time.
According to a second aspect of the invention, the above mentioned and other objectives are achieved with a second communication device for a communication system, the second communication device being configured to:
An advantage of the second communication device according to the second aspect is that the mapping of the four sets of information bits is performed in parallel, and is fully compatible with existing communication systems by providing the binary bits after de-mapping as so-called ‘new’ information bit for processing at the first communication device. The existing communication systems may be 3GPP NR but is not limited thereto.
In an implementation form of a second communication device according to the second aspect, the predetermined probability distribution function determines the occurrence of each amplitude in the first number of modulated symbols and in the second number of modulated symbols, respectively, from M number of predefined positive amplitudes.
In an implementation form of a second communication device according to the second aspect, the M number of predefined positive amplitudes are obtained from a pulse amplitude modulation.
In an implementation form of a second communication device according to the second aspect, the predetermined probability distribution function is a Gaussian or a near Gaussian probability distribution function.
An advantage with this implementation form is that to attain a given entropy, the Gaussian alphabet yields the least average-power of the constellation symbols compared to other symbol distributions. This means that transmit power can be increased proportional to the average-power decrement with the probabilistic constellation shaping, while the effective average transmit-power of the symbols remains unchanged. This means that the throughput can be increased in the communication system.
In an implementation form of a second communication device according to the second aspect,
the demodulating of the first number of signed bits and the second number of signed bits comprises map a sign bit 1 to an information bit 0 and a sign bit −1 to an information bit 1, or vice versa.
In an implementation form of a second communication device according to the second aspect,
the set of complex-valued modulated symbols are quadrature amplitude modulated symbols.
In an implementation form of a second communication device according to the second aspect,
the second communication device being configured to
An advantage with this implementation form is that the control signaling can be performed with low overhead.
In an implementation form of a second communication device according to the second aspect,
the predetermined probability density function is represented as a Gaussian distribution.
An advantage with this implementation form is that the Gaussian distribution can be represented by a single parameter which can be signaled to the second communication device.
In an implementation form of a second communication device according to the second aspect,
the second communication device being configured to
An advantage with this implementation form is that the control signaling can be performed with low overhead.
In an implementation form of a second communication device according to the second aspect,
the second communication device being configured to
An advantage with this implementation form is that the signaling overhead can be kept at a minimum, and the predetermined probability distribution function or the occurrences of all positive amplitudes can be given by a modulation and coding scheme table that is known to both the first and the second communication devices.
In an implementation form of a second communication device according to the second aspect,
the demodulation of the first set of modulated symbols and the second set of modulated symbols comprises
An advantage with this implementation form is that the processing of a large number of information bits may be performed in parallel thereby reducing implementation complexity and decreasing processing time.
According to a third aspect of the invention, the above mentioned and other objectives are achieved with a method for a first communication device, the method comprises:
The method according to the third aspect can be extended into implementation forms corresponding to the implementation forms of the first communication device according to the first aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the first communication device.
The advantages of the methods according to the third aspect are the same as those for the corresponding implementation forms of the first communication device according to the first aspect.
According to a fourth aspect of the invention, the above mentioned and other objectives are achieved with a method for a second communication device, the method comprises:
The method according to the fourth aspect can be extended into implementation forms corresponding to the implementation forms of the second communication device according to the second aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the second communication device.
The advantages of the methods according to the fourth aspect are the same as those for the corresponding implementation forms of the second communication device according to the second aspect.
Embodiments of the invention also relates to a computer program, characterized in program code, which when run by at least one processor causes the at least one processor to execute any method according to embodiments of the invention. Further, embodiments of the invention also relate to a computer program product comprising a computer readable medium and the mentioned computer program, wherein the computer program is included in the computer readable medium, and may comprises one or more from the group of: read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), flash memory, electrically erasable PROM (EEPROM), hard disk drive, etc.
Further applications and advantages of embodiments of the invention will be apparent from the following detailed description.
The appended drawings are intended to clarify and explain different embodiments of the invention, in which:
In communication systems, such as 3GPP 5G NR, uniformly distributed QAM symbol constellations are used. Probabilistic constellation shaping (PCS) is not supported in NR but there have been proposals of applying PCS for NR systems. However, mentioned proposals are based on probabilistic amplitude shaping (PAS), which firstly shapes the amplitudes, and then applies a systematic encoder, such as low-density parity check (LDPC) code, to generate parity bits that are mapped as signs of the amplitudes. Such proposals put a stringent constrain on the code-rate of the systematic code, and further the backwards compatibility to current NR system will not be good. Another proposal is to modify the encoder itself to produce coded bits with biased distribution, which however also requires significant changes in the current coding and decoding process in NR.
Therefore, it is herein disclosed a solution comprising a PCS modulation scheme for a communication system, which is clearly defined, flexible, practical, and backwards compatible to existing communication systems, such as the mentioned 5G NR. In addition, related control signaling to support the present PCS modulation scheme is also defined.
The processor 102 may be referred to as one or more general-purpose CPU, one or more digital signal processor (DSP), one or more application-specific integrated circuit (ASIC), one or more field programmable gate array (FPGA), one or more programmable logic device, one or more discrete gate, one or more transistor logic device, one or more discrete hardware component, or one or more chipsets. The memory 106 may be a read-only memory, a random access memory (RAM), or a non-volatile RAM (NVRAM). The transceiver 304 may be a transceiver circuit, a power controller, or an interface providing capability to communicate with other communication modules or communication devices, such as network nodes and network servers. The transceiver 104, memory 106 and/or processor 102 may be implemented in separate chipsets or may be implemented in a common chipset. That the first communication device 100 is configured to perform certain actions can in this disclosure be understood to mean that the first communication device 100 comprises suitable means, such as e.g., the processor 102 and the transceiver 104, configured to perform the actions.
According to embodiments of the invention and with reference to
The processor 302 may be referred to as one or more general-purpose CPU, one or more digital signal processor (DSP), one or more application-specific integrated circuit (ASIC), one or more field programmable gate array (FPGA), one or more programmable logic device, one or more discrete gate, one or more transistor logic device, one or more discrete hardware component, one or more chipset. The memory 306 may be a read-only memory, a random access memory (RAM), or a non-volatile RAM (NVRAM). The transceiver 104 may be a transceiver circuit, a power controller, or an interface providing capability to communicate with other communication modules or communication devices. The transceiver 304, the memory 306 and/or the processor 302 may be implemented in separate chipsets or may be implemented in a common chipset. That the second communication device 300 is configured to perform certain actions can in this disclosure be understood to mean that the second communication device 300 comprises suitable means, such as e.g., the processor 302 and the transceiver 304, configured to perform the actions.
According to embodiments of the invention and with reference to
With reference to
At the receiver side, the second communication device 300 receives the communication signal 510 comprising the complex-valued QAM symbols from the first communication device 100. The second communication device 300 initiates a detection procedure in the detection block 380. For example, the second communication device 300 estimate a set of log-likelihood ratios (LLRs) and decodes the set of LLRs into a set of decoded binary bits. If the decoding succeeds without error in the set of decoded binary bits, the second communication device 300 continues to the mapper block 360 and the PCS demodulation block 350, i.e., the inverse operations of the PCS operations implemented at the first communication device 100. However, if the decoding fails without error(s) in the set of decoded binary bits, the second communication device 300 may report a block error to the first communication device 100, and skip mentioned mapper block 360 and PCS demodulation block 350. The block error reporting to the first communication device 100 may be performed according to a HARQ procedure known in the art.
The inverse operations to the operations performed in the first communication device 100 are implemented in the mapper block 360 and in the PCS demodulation block 350, respectively. The mapper block 360 is configured to map the correctly decoded bits into a vector comprising QAM symbols. The PCS demodulation block 350 receives the vector of QAM symbols and performs an inverse DM operation to recover the transmitted information bits which are outputted as decoded bits at the second communication device 300.
Hence, it is herein disclosed a solution that makes it possible to keep the current NR transmitter chain unaltered with only adding a PCS modulation block 150 and a de-mapper block 160 before the systematic encoder 170 at the transmitter side. The PCS modulation block 150 processes a vector of input information bits into a vector of complex-valued QAM symbols, which applies two separate distribution matchers (DMs) in parallel, such as using arithmetic encoding, to shape the amplitudes of the real and imaginary parts of a complex-valued QAM symbol to follow the given predetermined probability distribution function. The predetermined probability distribution function, such as a Gaussian or a near Gaussian probability distribution function, determines the occurrence of each amplitude in the first number of modulated symbols and in the second number of modulated symbols, respectively, from M number of predefined positive amplitudes. The M number of predefined positive amplitudes may be obtained from a pulse amplitude modulation as previously described.
The first and second sign bits SB1, SB2 are generated from information bits by a mapping procedure in which the mapping of the second set of information bits IB2 and the fourth set of information bits IB4 comprises mapping an information bit 0 to a sign bit 1 and an information bit 1 to a sign bit −1, or vice versa. This may e.g., be achieved with BPSK or any other suitable mapping scheme. Finally, these four parts, i.e., the amplitudes of the real and imaginary parts and signs of the real and imaginary parts are combined together to create the shaped constellation QAM symbols. Afterwards, these QAM symbols are de-mapped into binary bits in the de-mapper block 160, and fed to the systematic encoder 170, which implies that all remaining processes or steps at transmission in NR can be unchanged. Such a general design yields a good backwards compatibility and also only requires small modifications to an existing communication system that only supports uniformly distributed symbol constellations.
For those systems where scrambling and interleaving are implemented at the coded bits produced by the systematic encoder, inverse operations may be further considered accordingly on the de-mapped bits to preserve the order of bits when it maps back to shaped QAM constellation symbols. On the other hand, since the parity bits, such as outputted from a LDPC encoder, is close to uniformly distributed, these parity bits are mapped to different constellation symbols with equal probability. Therefore, PCS is most useful with high code-rates such that the overall distribution of constellation symbols after encoding is still close to Gaussian.
Moreover,
In step I in
In step II in
In step II in
In step III in
In step IV in
For instance, for 256-QAM modulation, it holds that M=8 and log2 M=3, while for 1024-QAM modulation, it holds that M=16 and log2 M=4. Hence, on average each complex-valued QAM symbol carries 2+K/N number of bits. Lastly, the 4M2-QAM number of complex-valued modulated symbols CVMS are de-mapped in a demapper block 160 into a set of binary bits as have been explained with reference to
As aforementioned, a DM block maps an input length K binary bit sequence into a length N vector that comprises M positive amplitudes, and the probability distribution function (pdf) of the M positive amplitudes is following a Gaussian or a near Gaussian distribution. Such a pdf can be predetermined and adapted according to the transmission conditions such as the channel characteristics, SNR, modulation-order, code-rate, etc. In general, a discrete Gaussian distribution may be used as
for the mth amplitude Am from a predetermined set {A1, A2, . . . , AM}, for instance it can be set that Am=(2m−1)√{square root over (β)}. The normalization factor a equals to
such that Σm=1Mp(Am)=1.
In this case, the parameter v determines the pdf and may be considered as a design parameter. For instance, if v=0, then p(Am)=1/M for all amplitudes which follows a uniform distribution. With a uniform distribution, the average power of all constellation symbols is normalized to 1. As the value of v increases, the transmission probabilities of a constellation symbols increase as its amplitude decreases, which yields a smaller average power ε that equals to
Meanwhile, the entropy H (in natural unit of information) equals
where ‘ln’ denotes the natural logarithm, and a is defined in Eq. 2. With the PCS, the number of bits carried by each amplitude is reduced. Therefore, there is a trade-off between the entropy and average power. Nevertheless, it is known that to attain a given entropy in Eq. 4 the Gaussian distribution minimizes the averaged power in Eq. 3.
Now assuming that the DM block generates a length N vector that comprises M positive amplitudes, the occurrences Nm of each amplitude Am is equal to p(Am) i.e.,
Note that Nm must be an integer, and an adjustment to the amplitude p(Am) may be required, based on principles such as minimizing the Kullback-Leibler (KL) divergence i.e.
between the original pdf p=(p(A1), p(A2), . . . , p(AM)) and a revised pdf q=(q(A1), q(A2), . . . , q(AM)) such that Nm=Nq(Am) are all integers.
Nevertheless, we may assume that with an appropriate adjustment, all Nm are integers.
Then, considering all possible length N vectors such that amplitude Am exactly appears Nm times, the number of all such vectors is equal to
Therefore, it can support K=└log2 S┘ number of information bits to be able to index each input vector to such an output vector, where the operation ‘└log2 S┘’ takes the largest integer that is no larger than └log2 S┘. For instance, consider a case when the DM block outputs a vector of length N=24, and the four amplitudes appear {12,6,4,2} times, respectively. Then, in total the number of sequences satisfying this is
and the maximal number of input information bit will be
K=└log2 S┘=35.
In this non-limiting example p={0.5, 0.25, 0.17, 0.08}, and the entropy is H=1.726 bits. While for N=24, K=N, H=41.42 bits can in theory be carried, which is larger than 35 bits. This is because the length N in this case is small, and for K/N to be able to approach H, N should be sufficiently large.
Further embodiments of the invention for the DM operation are illustrated in
The first communication device 100 will split the first set of information bits IB1 into a number of first subsets of information bits in the serial to parallel conversion block 154. Each first subset of information bits will be modulated into a number of first subsets of modulated symbols based on the predetermined probability distribution function in the parallel sub-DM blocks 156, Sub-DM-1, Sub-DM-2, Sub-DM-J. The first subsets of modulated symbols from the parallel sub-DM blocks 156 will be combined into the first number of modulated symbols MS1 in the parallel to serial block 158. Correspondingly, first communication device 100 will also split the third set of information bits IB3 into a number of second subsets of information bits, modulate each second subset of information bits into a number of second subsets of modulated symbols based on the predetermined probability distribution function, and combine the second subsets of modulated symbols into the second number of modulated symbols MS2.
Not shown in the Figs, but the second communication device 100 will perform the corresponding inverse operations. That is, for demodulating the first set of modulated symbols MS1 and the second set of modulated symbols MS2, the second communication device 100 will split the first set of modulated symbols MS1 into a number of first subsets of modulated symbols. Each first subset of modulated symbols is modulated into a number of first subsets of information bits based on the predetermined probability distribution function. The first subsets of information bits are thereafter combined into the first number of information bits IB1. Correspondingly, the second communication device 100 will also split the second set of modulated symbols MS2 into a number of second subsets of modulated symbols, demodulate each second subset of modulated symbols into a number of second subsets of information bits based on the predetermined probability distribution function, and thereafter combine the second subsets of information bits into the third number of information bits IB3.
In the following section and with reference to
The first communication device 100 transmit a control signal 520 in step I in
Therefore, in an embodiment of the invention, the pair of parameters v, N can be assigned to the second communication device by assuming the pdf follows the Gaussian distribution in Eq. 1, together with some agreed adjustments to make all Ni to be integers. In other words, the first communication device 100 transmits a control signal 520 to the second communication device 300, where the control signal 520 indicates the predetermined probability density function, and the number symbols N in the first number of modulated symbols MS1 and in the second number of modulated symbols MS2. In examples of the invention, the predetermined probability density function may be represented as a Gaussian distribution in the mentioned control signaling.
In another embodiment, the values indicating the occurrences of M number of predefined positive amplitudes are signaled to the second communication device 100 e.g., with standard compression technics such as differential encoding to reduce the payload size. Hence, the first communication device 100 in this example transmits a control signal 520 to the second communication device 300, where the control signal 520 indicates the occurrences of M number of predefined positive amplitudes {N1, N2, . . . , NM} in the first number of modulated symbols MS1 and in the second number of modulated symbols MS2, respectively.
In yet another embodiment the modulation and coding schemes (MCSs) of NR are extended. Therefore, the first communication device 100 may transmit a control signal 520 to the second communication device 300, and the control signal 520 indicates a MCS associated with the transmission of the set of complex-valued modulated symbols 510.
In NR, the MCS for a certain transmission is determined via higher layer signaling, such as RRC signaling, using MCS tables. Instead of the explicit signaling of the PCS parameters according to the previous embodiments in this regard, an alternative is to modify the MCS tables to directly indicate the information needed by the second communication device 300 as illustrated in Table 1. The current MCS table for each MCS index (X) in NR contains information of modulation order (Q), target code-rate (R), and spectral efficiency (Y). An additional parameter can be added in MCS table e.g., in the form of [N1, N2, . . . , NM], where M as aforementioned equals to the number of different positive amplitudes in real or imaginary dimension for a given modulation order. Alternatively, the additional parameter can be given in the form of [p1, p2, . . . , pM] and N, where pm=p(Am) is the probability for each positive amplitude, and N is the total length of DM output vector. In yet another alternatively, by assuming the MB distribution is applied, the additional parameter can also be given in the form [v, N].
A network access node herein may also be denoted as a radio first communication device, an access first communication device, an access point (AP), or a base station (BS), e.g., a radio base station (RBS), which in some networks may be referred to as transmitter, “gNB”, “gNodeB”, “eNB”, “eNodeB”, “NodeB” or “B node”, depending on the standard, technology and terminology used. The radio first communication devices may be of different classes or types such as e.g., macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby the cell size. The radio first communication device may further be a station (STA), which is any device that contains an IEEE 802.11-conformant media access control (MAC) and physical layer (PHY) interface to the wireless medium (WM). The radio first communication device may be configured for communication in 3GPP related long term evolution (LTE), LTE-advanced, fifth generation (5G) wireless systems, such as new radio (NR) and their evolutions, as well as in IEEE related Wi-Fi, worldwide interoperability for microwave access (WiMAX) and their evolutions.
A client device herein may be denoted as a user device, a user equipment (UE), a mobile station, an internet of things (IoT) device, a sensor device, a wireless terminal and/or a mobile terminal, and is enabled to communicate wirelessly in a wireless communication system, sometimes also referred to as a cellular radio system. The UEs may further be referred to as mobile telephones, cellular telephones, computer tablets or laptops with wireless capability. The UEs in this context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile devices, enabled to communicate voice and/or data, via a radio access network (RAN), with another communication entity, such as another receiver or a server. The UE may further be a station (STA), which is any device that contains an IEEE 802.11-conformant media access control (MAC) and physical layer (PHY) interface to the wireless medium (WM). The UE may be configured for communication in 3GPP related long term evolution (LTE), LTE-advanced, fifth generation (5G) wireless systems, such as new radio (NR), and their evolutions, as well as in IEEE related Wi-Fi, worldwide interoperability for microwave access (WiMAX) and their evolutions.
Furthermore, any method according to embodiments of the invention may be implemented in a computer program, having code means, which when run by processing means causes the processing means to execute the steps of the method. The computer program is included in a computer readable medium of a computer program product. The computer readable medium may comprise essentially any memory, such as previously mentioned a read-only memory (ROM), a programmable read-only memory (PROM), an erasable PROM (EPROM), a flash memory, an electrically erasable PROM (EEPROM), or a hard disk drive.
Moreover, it should be realized that the first communication device and the second communication device comprise the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing or implementing embodiments of the invention. Examples of other such means, units, elements and functions are: processors, memory, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selecting units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, MSDs, TCM encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged together for performing the solution.
Therefore, the processor(s) of the first communication device and the second communication device may comprise, e.g., one or more instances of a central processing unit (CPU), a processing unit, a processing circuit, a processor, an application specific integrated circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The expression “processor” may thus represent a processing circuitry comprising a plurality of processing circuits, such as e.g., any, some or all of the ones mentioned above. The processing circuitry may further perform data processing functions for inputting, outputting, and processing of data comprising data buffering and device control functions, such as call processing control, user interface control, or the like.
Finally, it should be understood that the invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.
This application is a continuation of International Application No. PCT/EP2022/066580, filed on Jun. 17, 2022, the disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2022/066580 | Jun 2023 | WO |
| Child | 18981889 | US |
