Distributed multicarrier system-based digitally controllable scatterer technology

Abstract

The disclosure provides a control entity, a DCS node, and a first node for a multicarrier communication system comprising a plurality of communication nodes and one or more DCS nodes. The plurality of communication nodes comprises a first set of nodes including a first node, and a second set of nodes including a second node. The control entity is configured to distribute one or more processing tasks of a plurality of processing tasks of multicarrier modulation and demodulation to each of the first node, the second node, and the one or more DCS nodes, so that an overall distributed processing allows modulation and demodulation processing of the multicarrier communication system. The DCS node is configured to receive a first configuration for a first sub-DCS of the DCS from the control entity. The first node is configured to receive a first indication from the control entity.

Description

[0001]DISTRIBUTED MULTICARRIER SYSTEM-BASED DCS TECHNOLOGY TECHNICAL FIELDThe disclosure relates to wireless communication systems using a digitally controllable scatterer (DCS), particularly tomulticarrier communication systems. A DCS may be also referred to as a reconfigurable intelligent surface (RIS), an intelligent reflecting surface (IRS), a large intelligent surface (LIS), or a smart repeater. The disclosure provides a control entity for a multicarrier communication system comprising a plurality of communication nodes and one or more DCS nodes. The disclosurefurther provides a corresponding method and a computer program product.BACKGROUND Currently, the signal processing for multi-user multicarrier Fourier-based communication systems modulation anddemodulation in uplink and downlink, respectively, is performed at the user equipment (UE) level where the UE has priorknowledge of its allocated frequency subcarriers via means of signaling. These processing and signaling burdens can becomea bottleneck for the implementation of low-complexity UEs. In DCS-aided communications systems, the DCS is placed in a propagation environment with a transmitter and a receiver. TheDCS can be implemented as a surface composed of ^ scattering elements, and each scattering element provides the ability tocontrol the phase of its scattered signal. As depicted in FIG. 1, the DCS can be implemented as a single block or as multipleblocks, as plane surfaces or any type of surface, an aggregation of surfaces, or a subsurface of one or more DCSs.In state-of-the-art multi-user multicarrier Fourier-based communication systems, a UE must perform a direct Fouriertransformation (e.g., Fast Fourier Transform (FFT)) for downlink demodulation processing and must perform an inverse Fouriertransformation (e.g., Inverse Fast Fourier Transform (IFFT)) for uplink modulation processing. Furthermore, for both downlinkand uplink processing, the UE must know the carrier frequency and its frequency allocation given by its allocated subcarriers.This incurs required signaling for informing each UE of its corresponding frequency allocation.SUMMARYIn view of the above, this disclosure proposes a DCS-aided distributed multi-user multicarrier Fourier-based system. Anobjective is to alleviate the frequency allocation signaling at the communication nodes, for instance, the UE. Another objectiveis to distribute the signal processing burden between the DCS and the communication nodes, particularly, to delegate some ofthe Fourier transformation modulation / demodulation processing to the DCS. This and other objectives are achieved by thisdisclosure according to the solutions described in the independent claims. Advantageous implementations are further describedin the dependent claims. A first aspect of this disclosure provides a control entity for a multicarrier communication system that comprises a plurality of communication nodes and one or more DCS nodes, wherein the plurality of communication nodes comprises a first set of nodes and a second set of nodes, the first set of nodes comprises a first node, and the second set of nodes comprises a second node, wherein each DCS node comprises a plurality of controllable scattering elements, and the control entity is configured to: distribute one or more processing tasks of a plurality of processing tasks of multicarrier modulation and demodulation to each of the first node, the second node, and the one or more DCS nodes, so that an overall distributed processing allows modulation and demodulation processing of the multicarrier communication system.This proposed DCS-aided distributed multicarrier Fourier-based system alleviates the frequency allocation signaling at thecommunication nodes and distributes the signal processing burden between the DCS and the communication nodes. Thishappens by delegating some of the Fourier transformation modulation / demodulation processing to the DCS. As a result, thesolutions of this disclosure reduces the processing and signaling at the communication node side. It may be worth mentioningthat the proposed control entity may be implemented as a standalone entity. Alternatively, the control entity may be implemented in a base station, one of the communication nodes, any other entity in the network, or as a part of the DCS as well as a distributed implementation with backhaul communication.In an implementation form of the first aspect, the control entity is further configured to: determine a first sub-DCS and at leastone first subcarrier allocated to the first node, wherein the first sub-DCS comprises at least one controllable scattering elementof the one or more DCS nodes; and distribute the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation to each of the first node, second node, and the first sub-DCS, wherein the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first sub-DCS, when executed by the first sub-DCS, cause the first sub-DCS to scatter a first signal transmitted from thefirst node, wherein the first signal is a signal that has been processed through the processing tasks assigned by the control entityto the first node with or without a knowledge of the at least one first subcarrier at the first node, while allowing the second nodeto obtain a demodulated signal from the scattered first signal through the processing tasks assigned by the control entity to thesecond node, and / or scatter a second signal transmitted from the second node, wherein the second signal is a signal that hasbeen processed through the processing tasks assigned by the control entity to the second node, so as to allow the first node toobtain a demodulated signal from the scattered second signal through the processing tasks assigned by the control entity to thefirst node, with or without knowledge of the at least one first subcarrier at the first node.According to solutions of this disclosure, single or multiple DCS nodes are controlled by the control entity and are designed tobeam toward a particular communication node.In this way, the communication node does not need any knowledge of the frequency allocation map of its subcarriers and isrelaxed from associated processing. In an implementation form of the first aspect, the control entity is further configured to provide a first configuration to the first sub-DCS, wherein the first configuration comprises a first common phasor for the first sub-DCS, and a first specific phasor for each of the controllable scattering elements of the first sub-DCS.The sub-DCS may be configured via the configuration phasor vector which contains the configuration phasor of each elementof the sub-DCS, and element-specific phasors.In an implementation form of the first aspect, the first common phasor is computed based on the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the first sub-DCS; or wherein the first common phasor and the first specific phasor are computed based on the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the first sub-DCS.In an implementation form of the first aspect, the control entity is further configured to determine the first common phasor forthe first sub-DCS to enable the first sub-DCS to perform the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first sub-DCS by enabling the first sub-DCS to frequency shift an impinging signal transmitted from the first node through the processing tasks assigned by the control entity to the first node, and / or enabling the first sub-DCS to frequency shift an impinging signal transmitted from the second node through the processing tasks assigned by the controller to the second node; and determine the first specific phasor for each ofthe controllable scattering elements of the first sub-DCS to enable the first sub-DCS to perform the one or more processingtasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first sub-DCS by enabling the first sub-DCS to beam towards the first node.In particular, each sub-DCS applies a specific frequency shift to its impinging signal. The common phasor of each element ofthe sub-DCS may be designed using its allocated frequency. Element-specific phasors may be designed to beam toward thecorresponding communication node.In an implementation form of the first aspect, the control entity is further configured to determine the first common phasor forthe first sub-DCS based on a first frequency shift that is based on the at least one first subcarrier and that is allocated to the first sub-DCS. The frequency shift allocated to a sub-DCS is related to a subcarrier selected from the subcarriers allocated to the corresponding communication node. In an implementation form of the first aspect, the control entity is further configured to determine a baseband frequency of one of the at least one first subcarrier as the first frequency shift. In an implementation form of the first aspect, the first set of nodes further comprises a third node, and the control entity is configured to: determine a second sub-DCS and at least one second subcarrier allocated to the third node, wherein the secondsub-DCS comprises at least one controllable scattering element of the one or more DCS nodes; and distribute one or moreprocessing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation to each of the third node, the second node, and the second sub-DCS, wherein the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the second sub-DCS, when executed by the second sub-DCS,cause the second sub-DCS to: scatter a third signal transmitted from the third node, wherein the third signal is a signal that hasbeen processed through the processing tasks assigned by the control entity to the third node with or without a knowledge of the at least one second subcarrier at the third node, while allowing the second node to obtain the demodulated signal from thescattered third signal through the processing tasks assigned by the control entity to the second node, and / or scatter a fourthsignal transmitted from the second node, wherein the fourth signal is a signal that has been processed through the processingtasks assigned by the control entity to the second node, so as to allow the third node to obtain a demodulated signal from the scattered fourth signal through the processing tasks assigned by the control entity to the third node, with or without knowledge of the at least one second subcarrier at the third node. This disclosure may also apply to a multi-user multicarrier Fourier-based communication system. Based on this disclosure,single or multiple DCS nodes are controlled by the control entity and are designed to create multiple beams (e.g., by means ofmultiple sub-DCSs) with each communication node being allocated at least a single beam.In an implementation form of the first aspect, the control entity is further configured to provide a second configuration to thesecond sub-DCS, wherein the second configuration comprises a second common phasor for the second sub-DCS, and a second specific phasor for each of the controllable scattering elements of the second sub-DCS. In an implementation form of the first aspect, the second common phasor is computed based on the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the secondsub-DCS; or wherein the second common phasor and the second specific phasor are computed based on the one or moreprocessing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to thesecond sub-DCS. In an implementation form of the first aspect, the control entity is further configured to determine a sub-DCS allocation for the first set of nodes, wherein the sub-DCS allocation indicates that the first sub-DCS is allocated to the first node; or wherein the sub-DCS allocation indicates that the first sub-DCS is allocated to the first node and the second sub-DCS is allocated to the third node. In an implementation form of the first aspect, the control entity is further configured to determine a subcarrier allocation for the first set of nodes, wherein the subcarrier allocation indicates that the at least one first subcarrier is allocated to the first node;or wherein the subcarrier allocation indicates that the at least one first subcarrier is allocated to the first node and the at leastone second subcarrier is allocated to the third node. In an implementation form of the first aspect, the control entity is further configured to determine the subcarrier allocation based on a predefined pattern, or based on a subcarrier allocation input.In the case where there is no input subcarrier allocation to the controller, or an input subcarrier allocation is unfeasible, thenthe controller performs subcarrier allocation. In an implementation form of the first aspect, the predefined pattern of each node of the first set of nodes indicates to distribute the allocated subcarriers of each node of the first set of nodes uniformly across all subcarriers of the multiuser multicarrier communication system.In an implementation form of the first aspect, the control entity is further configured to receive the subcarrier allocation inputfrom an external entity, wherein the subcarrier allocation input indicates one or more subcarriers that are allocated to one ormore nodes of the first set of nodes, verify the subcarrier allocation input is feasible, and determine the sub-DCS allocation tobe consistent with the subcarrier allocation input if the subcarrier allocation input is verified. If the subcarrier allocation is provided as an input to the controller then the controller functionality consists first in verifyingthat the provided subcarrier allocation to communication nodes is feasible. If the input subcarrier allocation is feasible then thecontroller does not need to do any further allocation. In an implementation form of the first aspect, the control entity is further configured to determine the sub-DCS allocation randomly, or in one of the following manners: -based on link budgets among the nodes of the first set of nodes,- based on a lookup table between the nodes of the first set of nodes and sub-DCSs of the one or more DCSs, or- based on distances between the nodes of the first set of nodes and sub-DCSs of the one or more DCSs.In an implementation form of the first aspect, the control entity is further configured to provide a first indication to the firstnode, wherein the first indication indicates the one or more processing tasks that are distributed for the first node, and / or providea second indication to the second node, wherein the second indication indicates the one or more processing tasks that aredistributed for the second node, and / or provide a third indication to the third node, wherein the third indication indicates theone or more processing tasks that are distributed for the third node, and / or provide a fourth indication to the one or more DCSnodes, wherein the fourth indication indicates the one or more processing tasks that are distributed for the first sub-DCS, and / or provide a fifth indication to the one or more DCS nodes, wherein the fifth indication indicates the one or more processing tasks that are distributed for the second sub-DCS.The control entity in the system provides configuration information to other nodes in order to distribute the signal processingburden between the DCS nodes and the communication nodes. In an implementation form of the first aspect, the first indication comprises a quantity of the subcarriers of the at least one first subcarrier that are allocated to the first node, and / or the third indication comprises a quantity of the subcarriers of the at least one second subcarrier that are allocated to the third node. In an implementation form of the first aspect, the control entity is further configured to obtain a first uplink frequency for thefirst node to use for transmission; and / or obtain a second uplink frequency for the third node to use for transmission.In an implementation form of the first aspect, the first indication further comprises the first uplink frequency, and / or the third indication further comprises the second uplink frequency. In an implementation form of the first aspect, the first uplink frequency and / or the second uplink frequency are a common frequency, or randomly selected.In an implementation form of the first aspect, at least one of the first indication, the second indication, the third indication, thefourth indication, and the fifth indication, comprises a duration of an overall symbol and / or a duration of a cyclic prefix of the multicarrier communication system. In an implementation form of the first aspect, the second indication further comprises the subcarrier allocation.A second aspect of this disclosure provides a DCS node for a multicarrier communication system comprising a plurality ofcommunication nodes, wherein the plurality of communication nodes comprises a first set of nodes and a second set of nodes, the first set of nodes comprises a first node, and the second set of nodes comprises a second node, wherein the DCS nodecomprises a plurality of controllable scattering elements, wherein the DCS node is divided into a plurality of sub-DCS, whereineach sub-DCS comprises a subset of the plurality of controllable scattering elements in the DCS, and the DCS is configured to: receive, from a control entity, a first configuration for a first sub-DCS of the DCS, wherein the first configuration comprises a first common phasor for the first sub-DCS, and a first specific phasor for each of the controllable scattering elements of the first sub-DCS, wherein the first common phasor is computed based on one or more processing tasks of a plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the first sub-DCS by the control entity.In this disclosure, single or multiple DCS nodes are controlled by a controller and may be designed to create multiple beams(e.g., by means of multiple sub-DCSs) with each communication node being allocated a single beam (e.g., a single sub-DCS).In an implementation form of the second aspect, the first sub-DCS is configured to: frequency shift an impinging signaltransmitted from the first node, and / or frequency shift an impinging signal transmitted from the second node, based on the first common phasor of the first sub-DC; and scatter an impinging signal towards the first node based on the first specific phasor of each of the controllable scattering elements of the first sub-DCS.Each sub-DCS applies a specific frequency shift to its impinging signal with the configured common phasor. Element-specificphasors are configured to beam toward the corresponding communication node. In an implementation form of the second aspect, the first common phasor indicates a first frequency shift that is provided to the first sub-DCS.The DCS common phasor of each sub-DCS is configured using the frequency shift associated with that sub-DCS.In an implementation form of the second aspect, the first frequency shift is a baseband frequency of one of at least one first subcarrier that is allocated to the first node. The frequency shift allocated to a sub-DCS is related to a subcarrier selected from the subcarriers allocated to the corresponding communication node. In an implementation form of the second aspect, the first set of nodes further comprises a third node, and the DCS is configured to: receive, from the control entity, a second configuration for a second sub-DCS, wherein the second configuration comprises a second common phasor for the second sub-DCS, and a second specific phasor for each of the controllable scattering elements of the second sub-DCS, wherein the second common phasor is computed based on the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the second sub-DCS by the control entity. In an implementation form of the second aspect, the DCS node is configured to receive a sub-DCS allocation configuration from the control entity, wherein the sub-DCS allocation configuration indicates that the first sub-DCS is allocated to the first node, and / or the second sub-DCS is allocated to the third node. In an implementation form of the second aspect, the controllable scattering elements comprised in each sub-DCS are adjacent and / or non-adjacent.In an implementation form of the second aspect, the DCS node is configured to receive a fourth indication from the controlentity, wherein the fourth indication indicates the one or more processing tasks that are distributed to the first sub-DCS, and / or receive a fifth indication from the control entity, wherein the fifth indication indicates the one or more processing tasks that are distributed to the second sub-DCS. A third aspect of this disclosure provides a first node for a multicarrier communication system that comprises a plurality of communication nodes, and one or more DCS nodes, wherein the plurality of communication nodes comprises a first set of nodes and a second set of nodes, the first set of nodes comprises the first node, and the second set of nodes comprises a secondnode, wherein each DCS comprises a plurality of controllable scattering elements, and the first node is configured to receive,from a control entity, a first indication, wherein the first indication indicates one or more processing tasks of a plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first node by the control entity.This disclosure provides a first node, i.e., a DCS-aided UE, with simplified processing. For both the uplink and downlink cases,the UE does not need any knowledge of the frequency allocation map of its subcarriers and is relaxed from associated processing. In an implementation form of the third aspect, the one or more processing tasks comprise a summation process. In an implementation form of the third aspect, the first indication further comprises a duration of an overall symbol and / or aduration of a cyclic prefix of the multicarrier communication system, and the first node is configured to: receive, from thesecond node, at least one signal; and perform a summation process on received samples of the at least one signal, based on theduration of the overall symbol and / or the duration of the cyclic prefix. In an implementation form of the third aspect, the first node is further configured to obtain a demodulated signal by inputting an output of the summation process into a Fourier transformation demodulator. In the downlink, each UE may extract its subcarriers by first conducting a number of summations of different distributed samples of the received signal, then providing the summation outputs to the Fourier transformation demodulator (e.g., FFT) with a size that corresponds to the number of its allocated subcarriers that are less or equal than the number of total allocated subcarriers at the base station level. In an implementation form of the third aspect, wherein the first indication further comprises a quantity M that indicates aquantity of subcarriers that is allocated to the first node, M being a positive integer.In an implementation form of the third aspect, when M is equal to 1, the first node is configured to perform the summationprocess by accumulating the received samples of the at least one signal over the duration of the overall symbol minus the duration of the cyclic prefix. In an implementation form of the third aspect, when M is greater than or equal to 2, the first node is configured to perform the summation process by computing one or more summations wherein each summation is generated by accumulating interleaved received samples of the at least one signal. Each DCS-aided UE does a number of summation processes on different samples of its received signal. During each summation process, the DCS-aided UE accumulates a set of distributed samples of the received signal. In an implementation form of the third aspect, the first node is further configured to obtain the demodulated signal by inputting the one or more summations into the Fourier transformation demodulator. The outputs of the summation processes are provided to the multicarrier-based Fourier transformation demodulator (e.g., FFT),where the DCS-aided UE does not need to know its allocated set of subcarriers for extracting its information symbols.In an implementation form of the third aspect, the summation process is performed by computing M summations and the demodulated signal is obtained by inputting the M summations into the Fourier transformation demodulator, wherein a minimum required size of the Fourier transformation demodulator is equivalent to M. In an implementation form of the third aspect, the first indication further comprises a first uplink frequency for transmission,and the first node is configured to transmit a signal using the first uplink frequency over the duration of the overall symbol.In the uplink case, each UE modulates the information symbols via Fourier transformation with a size that corresponds to the number of its allocated subcarriers that are less than or equal to the number of total allocated subcarriers at the base station level. The UE then sends consecutive copies of its constructed multicarrier Fourier-based symbol over a given carrier frequency. Notably, the UE does not need any knowledge of the frequency allocation map of its subcarriers and is relaxed from associated processing. In an implementation form of the third aspect, the first uplink frequency is preconfigured in the first node, or provided by the control entity.In an implementation form of the third aspect, the first node is further configured to construct the signal based on the quantityM, wherein the signal comprises an M size orthogonal frequency-division multiplexing (OFDM) symbol; and transmit aplurality of consecutive copies of the OFDM symbol using the first uplink frequency over the duration of the overall symbol.A fourth aspect of this disclosure provides a wireless communication system comprising a control entity according to the firstaspect or any of its implementation forms, one or more DCS nodes, each DCS node according to the second aspect or any ofits implementation forms, and a plurality of communication nodes comprising a first set of nodes and a second set of nodes, the first set of nodes comprises the first node according to the third aspect or any of its implementation forms, and the second set of nodes comprises a second node.A fifth aspect of the disclosure provides a method for a multicarrier communication system that comprises a plurality ofcommunication nodes and one or more DCS nodes, wherein the plurality of communication nodes comprises a first set of nodes and a second set of nodes, the first set of nodes comprises a first node, and the second set of nodes comprises a second node, wherein each DCS comprises a plurality of controllable scattering elements, the method being performed by a control entity and comprising: distributing one or more processing tasks of a plurality of processing tasks of multicarrier modulation and demodulation to each of the first node, the second node, and the one or more DCS nodes, so that an overall distributed processing allows modulation and demodulation processing of the multicarrier communication system.Implementation forms of the method of the fifth aspect may correspond to the implementation forms of the control entity ofthe first aspect described above. The method of the fifth aspect and its implementation forms achieve the same advantages andeffects as described above for the control entity of the first aspect and its implementation forms.A sixth aspect of the disclosure provides a method for a multicarrier communication system that comprises a plurality ofcommunication nodes, wherein the plurality of communication nodes comprises a first set of nodes and a second set of nodes, the first set of nodes comprises a first node, and the second set of nodes comprises a second node, the method being performed by a DCS node, comprising a plurality of controllable scattering elements, wherein the DCS is divided into a plurality of sub- DCS, wherein each sub-DCS comprises a subset of the plurality of controllable scattering elements in the DCS, and the method comprising: receiving, from a control entity, a first configuration for a first sub-DCS of the DCS, wherein the first configuration comprises a first common phasor for the first sub-DCS, and a first specific phasor for each of the controllable scattering elements of the first sub-DCS, wherein the first common phasor is computed based on one or more processing tasks of a plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the first sub-DCS by the control entity.Implementation forms of the method of the sixth aspect may correspond to the implementation forms of the DCS node of thesecond aspect described above. The method of the sixth aspect and its implementation forms achieve the same advantages andeffects as described above for the DCS node of the second aspect and its implementation forms.A seventh aspect of the disclosure provides a method for a multicarrier communication system that comprises a plurality ofcommunication nodes and one or more DCS nodes, wherein the plurality of communication nodes comprises a first set of nodes and a second set of nodes, the first set of nodes comprises the first node, and the second set of nodes comprises a second node, wherein each DCS comprises a plurality of controllable scattering elements, the method being performed by the first node and comprising: receiving, from the control entity, a first indication, wherein the first indication indicates one or more processing tasks of a plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first node by the control entity.Implementation forms of the method of the seventh aspect may correspond to the implementation forms of the first node of thethird aspect described above. The method of the seventh aspect and its implementation forms achieve the same advantages andeffects as described above for the first node of the third aspect and its implementation forms.An eighth aspect of the disclosure provides a computer program product comprising a program code for carrying out, whenimplemented on a processor, the method according to the fifth aspect or its implementation forms, the sixth aspect or itsimplementation forms, or the seventh aspect or its implementation forms.A ninth aspect of the disclosure provides a computer-readable medium comprising instructions which, when executed by acomputer, cause the computer to carry out, the method according to the fifth aspect or its implementation forms, the sixth aspector its implementation forms, or the seventh aspect or its implementation forms.It has to be noted that all devices, elements, units, and means described in the present application could be implemented in thesoftware or hardware elements or any kind of combination thereof. All steps that are performed by the various entities describedin the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the followingdescription of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in thedescription of a specific detailed element of that entity that performs that specific step or functionality, it should be clear for askilled person that these methods and functionalities can be implemented in respective software or hardware elements or any kind of combination thereof. BRIEF DESCRIPTION OF DRAWINGS The above-described aspects and implementation forms will be explained in the following description of specific embodimentsin relation to the enclosed drawings, in whichFIG. 1 shows exemplary DCS scattering surfaces;FIG. 2 show an example of a DCS-aided wireless communication system;FIG. 3 shows a control entity according to an embodiment of this disclosure;FIG. 4 shows an exemplary DCS-aided multi-user multicarrier Fourier-based system according to an embodimentof this disclosure;FIG. 5 shows an exemplary DCS-aided multi-user multicarrier Fourier-based system according to an embodimentof this disclosure;FIG. 6 shows exemplary sub-DCSs according to an embodiment of this disclosure;FIG. 7 shows an exemplary DCS-aided multi-user multicarrier Fourier-based system according to an embodimentof this disclosure;FIG. 8 shows an example of exchanged information between the control entity, a first node, a DCS, and a secondnode according to an embodiment of this disclosure;FIG. 9 shows an example of exchanged information between the control entity, a first node, a DCS, and a secondnode according to an embodiment of this disclosure;FIG. 10 shows a method for a control entity according to an embodiment of this disclosure;FIG. 11 shows a method for a DCS node according to an embodiment of this disclosure; andFIG. 12 shows a method for a first node according to an embodiment of this disclosure.DETAILED DESCRIPTION OF EMBODIMENTS Illustrative embodiments of a control entity, a DCS node, a first node, and corresponding methods for a multicarriercommunication system are described in the following with reference to the figures. Although this description provides a detailedexample of possible implementations, it should be noted that the details are intended to be exemplary and in no way limit the scope of the application.Moreover, an embodiment or example may refer to other embodiments or examples. For example, any description includingbut not limited to terminology, element, process, explanation, and / or technical advantage mentioned in one embodiment or example may also apply to the other embodiments or examples. For ease of understanding of this disclosure, DCS is first introduced here. The DCS is composed of a number of controllable scattering elements and can be implemented as a single block or as multiple blocks, as plane surfaces or any type of surface,an aggregation of surfaces, or subsurface of DCSs, as depicted in FIG. 1.FIG. 2 illustrates an example of a DCS-aided communications system, in which three communication nodes (UE nodes) arecommunicating with a transmitter, with the support of a DCS.FIG.3 shows a control entity 300 for a multicarrier communication system that comprises a plurality of communication nodes 310 and one or more DCS nodes 320, wherein the plurality of communication nodes 310 comprises a first set of nodes and a second set of nodes, the first set of nodes comprises a first node 311, and the second set of nodes comprises a second node 312, wherein each DCS node 320 comprises a plurality of controllable scattering elements. The control entity 300 is configured to distribute one or more processing tasks 301, 302, 303 of a plurality of processing tasks of multicarrier modulation and demodulation to each of the first node 311, the second node 312, and the one or more DCS nodes 320, so that an overall distributed processing allows modulation and demodulation processing of the multicarrier communication system. The control entity 300 according to this disclosure may comprise a processor or processing circuitry (not shown) configured toperform, conduct, or initiate the various operations of control entity 300 described herein. The processing circuitry maycomprise hardware and / or the processing circuitry may be controlled by software. The hardware may comprise analog circuitry digital circuitry, or both analog and digital circuitry. The digital circuitry may comprise components such as application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), digital signal processors (DSPs), or multi-purpose processors. The control entity 300 may further comprise memory circuitry, which stores one or more instruction(s) that can be executed by the processor or by the processing circuitry, in particular under the control of the software. For instance, the memory circuitry may comprise a non-transitory storage medium storing executable software code which, when executed by the processor or the processing circuitry, causes the various operations of the control entity 300 to be performed. The processing circuitry may comprise one or more processors and a non-transitory memory connected to the one or more processors. The non-transitory memory may carry executable program code which, when executed by the one or more processors, causes the control entity300 to perform, conduct, or initiate the operations or methods described herein.For ease of understanding the present disclosure, an exemplary implementation of the system shown in FIG.2 is first explainedhere. In this example, the system may be an OFDM system, a user ^ is assigned a set of subcarriers ^ ∈ Ω^ and where themodulation and demodulation are performed via Fourier transformation processing.At user ^ the Fourier transformation modulation that maps the symbols ^(^ ∈ Ω^) to its allocated subcarriers ^^ for signaltransmission (e.g. uplink) is written as follows: ^^(^) = ∑^∈^ ^^^^ ^^ ^ ^ ^(^), 0 ≤ ^ < ^^ , Eq. 1where ^ = ^^^ with ^^ being the sampling period and ^ denoting the ^-th sample.The Fourier transformation demodulation process that extracts the ^-^ℎ subcarrier of the received signal at user ^ ^^(^) couldbe written as: ^^(^) = ∑^^^^^^^^ ^^^^^^^^^^(^) , Eq. 2where ^^(^) is the received (e.g. downlink) signal at one receiving antenna of the plurality of the receiving antennas from atransmitter antenna of the plurality of the transmitting antennas.^^(^) could be written as follows: where ^^^(^) is the signal sent by the base station.^^^(^) could be written as follows: where ^^(^) denotes the information symbol to be modulated over the ^-th subcarrier.^ ^^(^) denotes the demodulated information symbol over the ^-th subcarrier.^ ^^ denotes the k-th subcarrier frequency.^ ^ denotes the total number of subcarriers.^ Ω^ denotes the set of subcarrier indices that are allocated to the s-th user equipment (UE).^ ^^ = |Ω^| denotes the number of subcarriers allocated to the ^-th UE.^ ^^^ denotes the number of served UEs.^ ^^ denotes the time duration of the multicarrier waveform symbol.^ ^^ ∈ ℂ^×^ is the additive noise.^ ^^ = ^^^^^^^^^ , ^^^, ^^^^^^^^ ^ is the complex channel gain the UE ^ experiences through the DCS. In most ofthe cases, it is written as ^^ = ^^,^(^)^^^ where ^^,^ ∈ ℂ^×^represents the concatenated channel with ^^,^= ℎ^^^^^^^^^^^ℎ^^^^^^^^. ^^^^^^^^ ∈ ℂ^×^is the channel vector that represents the electromagnetic environment the transmitting signal goes through to reach the DCS elements.^ ^^^^^^^^ ∈ ℂ^×^is the channel vector that represents the electromagnetic environment the scattered signal from the DCS goes through to reach the receiving node. ^^ denotes the number of DCS elements.^ ^(^) ∈ ℂ^×^ is the DCS configuration vector and could be written as follows ^∈ ℂ^×^ is the DCS common phasor. In other words, it is common for all DCS elements.^ ^^^ ∈ ℂ^×^ is the vector of DCS element-specific phasors.It may be worth emphasizing that ^(^) and ^(^) are the baseband versions of transmitted and received signals, respectively,where the signal ^(^) is upconverted to a certain carrier frequency ^^, which is known by the communicating nodes, andtransmitted, as follows: The receiver-end starts by retrieving baseband signal from the received signal, thus, getting the received baseband signal of equation Eq.5 after sampling.As was previously described in the conventional multi-user multicarrier Fourier-based communication systems, a UE ^ mustperform a direct Fourier transformation (e.g., FFT) for downlink demodulation processing (as shown in Eq.2) and must perform an inverse Fourier transformation (e.g., IFFT) for uplink modulation processing (as shown in Eq. 1). Furthermore, for bothdownlink and uplink processing, a UE must know its frequency allocation given by its allocated subcarriers ^ ∈ Ω^. This incursrequired signaling in order to inform each UE of its corresponding frequency allocation Ω^.In order to reduce the modulation / demodulation processing, frequency allocation, and the related signaling requirements forthe communication nodes, this disclosure proposes a distributed multi-user multicarrier Fourier-based system using DCStechnology, which offers reduced signaling and complexity to communication nodes by distributing the Fourier transformationprocessing between the communication nodes and the DCS.This disclosure applies to the general scenario of two communicating nodes, Node1 (i.e., the first node 311) and Node2 (i.e.,the second node 312). The most common use case corresponds to Node1 being a UE and Node2 being a base station. This exemplary use case is described in the following for the description of the idea. In particular, a distributed multi-user multicarrier Fourier-based system using the DCS technology is proposed, where theobjective is to relax requirements on the communication nodes, i.e., the first set of nodes, from subcarrier allocation signalingand reduce related processing. In other words, the UEs are not required anymore to learn their allocated subcarriers Ω^, also the modulation and demodulation processing efforts are reduced. This becomes possible by distributing the Fourier transformation MODEM (MODulator-DEModulator) processing among the communication nodesand DCS nodes. It may be worth mentioning that said distribution among the nodes stands rather for an assignment with no notion of equality. The modempart that is delegated to the DCS carries information related to the allocated subcarriers. Hence, the UE is left to do some lowercomplexity processing to complete the Fourier transformation modem process.FIG. 4 shows a DCS-aided multicarrier communication system according to an embodiment of this disclosure. The multicarriercommunication system may comprise a plurality of communication nodes 310 and one or more DCS nodes 320. The pluralityof communication nodes comprises a first set of nodes and a second set of nodes. The first set of nodes comprises a first node311, e.g., Node1 as shown in FIG.4. Node1 may be a user node, and the first set of nodes may comprise a plurality of suchuser nodes. The second set of nodes comprises a second node 312, e.g., Node2 as shown in FIG. 4, which may be a base stationand the second set of nodes may comprise a plurality of such base station nodes. Each DCS node 320 comprises a plurality ofcontrollable scattering elements, and a sub-DCS 320-1 as shown in FIG.4 may comprise a subset of the plurality of controllablescattering elements. A detailed description of the functionalities of each node within the proposed DCS-aided system in this disclosure in both uplink and downlink cases is provided as follows.A (non-ordered) list of functionalities performed by the controller entity 300 are similar between uplink and downlink and aregiven as follows: ^Allocating the ^-th sub-DCS to the ^-th UE where each sub-DCS represents a set of DCS elements that areallocated to a UE. This set could contain elements from one or more DCSs. ^If the subcarrier allocation is provided as an input to the controller then the controller functionality consists first ofverifying that the provided subcarrier allocation to UEs is feasible. If the input subcarrier allocation is feasible then the controller does not need to do any further allocation. However, if the input subcarrier allocation is unfeasible then the controller performs subcarrier allocation in order to reposition the unfeasible ones. In the case where there is no input subcarrier allocation to the controller then the controller performs the subcarrier allocation. A feasible subcarrier allocation corresponds to one where the ^-th UE is allocated a set of subcarriers Ω^ that are distributedover the available systems’ subcarriers following a specific design that renders the distributed multi-user multicarrier Fourier-based system concept feasible. It is worth emphasizing that although a UE is allocated a set ofsubcarriers by the controller, the knowledge of this allocation is not provided to the UE but used by the DCS and base station nodes. ^Allocating a frequency shift ^^ to the s-th sub-DCS where ^ ∈ Ω^.^ Synchronizing between the distributed multicarrier waveform-based Fourier transformation system nodes: the UEs,the sub-DCSs, and the base station.Notably, in the downlink, the base station (the second node 312) creates and transmits the multi-user multicarrier Fourier-basedsymbol based on subcarrier allocation sets Ω^ of each UE, conventionally. For the uplink, the proposed DCS-aided distributedmulti-user multicarrier Fourier-based system allows the base station to deploy conventional multicarrier Fourier transformation-based waveforms demodulation processing based on the subcarrier allocation sets of each UE.This disclosure further proposes a DCS node 320 for a multicarrier communication system comprising a plurality ofcommunication nodes 310, as shown in FIG. 3. The plurality of communication nodes 310 comprises a first set of nodes and asecond set of nodes, the first set of nodes comprises a first node 311, and the second set of nodes comprises a second node 312.The DCS node 320 comprises a plurality of controllable scattering elements, wherein the DCS node 320 is divided into aplurality of sub-DCS, wherein each sub-DCS comprises a subset of the plurality of controllable scattering elements in the DCS node 320.The DCS node 320 is configured to receive, from a control entity 300, a first configuration for a first sub-DCS 320-1 of theDCS node 320. The control entity 300 may be the control entity as shown in FIG. 3 or FIG. 4. In particular, the firstconfiguration comprises a first common phasor for the first sub-DCS 320-1, and a first specific phasor for each of thecontrollable scattering elements of the first sub-DCS 320-1. The first common phasor is computed based on one or moreprocessing tasks of a plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to thefirst sub-DCS 320-1 by the control entity 300. Notably, the controllable scattering elements comprised in each sub-DCS may be adjacent and / or non-adjacent.For both uplink and downlink, the ^-th sub-DCS is configured via the configuration phasor vector ^^(^) ∈ ℂ^^×^whichcontains the configuration phasor of each element of the ^-^ℎ sub-DCS. ^^ denotes the number of elements of the s-th sub-DCS. ^^(^) is designed as follows: ^^^^^(^) ∈ ℂ^×^ is the ^-th sub-DCS common phasor where it is designed using its allocated frequency ^^ as follows:^ ^^^^(^) = ^^^^^^^^^^^^ ∈ ℂ^^×^ is the vector of the ^-^ℎ sub-DCS element-specific phasors. This is designed tobeam toward the ^-th UE.According to an embodiment of this disclosure, the first sub-DCS 320-1 is configured to frequency shift an impinging signaltransmitted from the first node 311, and / or frequency shift an impinging signal transmitted from the second node 312, basedon the first common phasor of the first sub-DCS 320-1. The first sub-DCS 320-1 may be further configured to scatter animpinging signal towards the first node 311 based on the first specific phasor of each of the controllable scattering elements ofthe first sub-DCS 320-1.Optionally, the first common phasor indicates a first frequency shift that is provided to the first sub-DCS 320-1. Optionally,the first frequency shift is a baseband frequency of one of at least one first subcarrier that is allocated to the first node 311.It may be understood that there may be multiple UEs in the system, that is, the first set of nodes further comprises a third node313. In this case, the DCS node 320 is further configured to receive, from the control entity 300, a second configuration for asecond sub-DCS 320-2, wherein the second configuration comprises a second common phasor for the second sub-DCS 320-2, and a second specific phasor for each of the controllable scattering elements of the second sub-DCS 320-2, wherein the second common phasor is computed based on the one or more processing tasks of the plurality of processing tasks of the multicarriermodulation and demodulation that are distributed to the second sub-DCS 320-2 by the control entity 300.According to an embodiment of this disclosure, the DCS node 320 is configured to receive a sub-DCS allocation configurationfrom the control entity 300, wherein the sub-DCS allocation configuration indicates that the first sub-DCS 320-1 is allocatedto the first node 311, and / or the second sub-DCS 320-2 is allocated to the third node 313.This disclosure further proposes a first node 311 for a multicarrier communication system comprising a plurality ofcommunication nodes 310, as shown in FIG. 3 or FIG. 4. The plurality of communication nodes 310 comprises a first set ofnodes and a second set of nodes, the first set of nodes comprises a first node 311, and the second set of nodes comprises asecond node 312. The DCS node 320 comprises a plurality of controllable scattering elements.The first node 311 is configured to receive a first indication from a control entity 300. The control entity 300 may be the controlentity 300 as shown in FIG. 3 or FIG. 4. In particular, the first indication indicates one or more processing tasks 301 of aplurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first node 311 by thecontrol entity 300. Possibly, the one or more processing tasks 301 comprise a summation process. In the downlink, each DCS-aided UE, i.e., the first node 311, does a number of summation processes on different samples of its received signal. During each summation process, the DCS-aided UE accumulates a set of distributed samples of the received signal. The outputs of the summation processes are provided to the multicarrier-based Fourier transformation demodulator (e.g., FFT), where the DCS-aided UE may not need to know its allocated set of subcarriers, Ω^, in order to extract its information symbols.It should be noted that this disclosure supports the conventional case where UEs are not aided by the DCS (zero DCS-aidedUE), thus, they are required to do the conventional multicarrier processing and related signaling. Optionally, the first indication further comprises a duration of an overall symbol and / or a duration of a cyclic prefix of themulticarrier communication system, and the first node 311 is configured to receive, from the second node 312, at least onesignal; and perform a summation process on received samples of the at least one signal, based on the duration of the overallsymbol and / or the duration of the cyclic prefix.Optionally, the first node 311 is configured to obtain a demodulated signal by inputting an output of the summation processinto a Fourier transformation demodulator. The first indication may further comprise a quantity M that indicates a quantity of subcarriers that is allocated to the first node 311, M being a positive integer.When M is equal to 1, the first node 311 is configured to perform the summation process by accumulating the received samplesof the at least one signal over the duration of the overall symbol minus the duration of the cyclic prefix. When M is greaterthan or equal to 2, the first node 311 is configured to perform the summation process by computing one or more summationswherein each summation is generated by accumulating interleaved received samples of the at least one signal.Optionally, the first node 311 is configured to obtain the demodulated signal by inputting the one or more summations into theFourier transformation demodulator.Notably, the summation process is performed by computing M summations and the demodulated signal is obtained by inputtingthe M summations into the Fourier transformation demodulator, wherein a minimum required size of the Fourier transformation demodulator is equivalent to M. In uplink, each UE (the first node 311) performs a Fourier-based modulation of its information symbols that does not require the knowledge of its allocated subcarriers. In other words, different from state-of-the-art, all UEs might modulate theirinformation symbols on the same subcarriers. The UE then sends consecutive copies of the created multicarrier symbol over agiven carrier frequency. Optionally, the first indication further comprises a first uplink frequency for transmission. In this case, the first node 311 isconfigured to transmit a signal using the first uplink frequency over the duration of the overall symbol.Possibly, the first uplink frequency is preconfigured in the first node 311, or provided by the control entity 300.According to an embodiment of this disclosure, the first node 311 is further configured to construct the signal based on thequantity M, wherein the signal comprises an M size OFDM symbol; and transmit a plurality of consecutive copies of the OFDMsymbol using the first uplink frequency over the duration of the overall symbol.FIG.5 shows an embodiment of a multi-user multicarrier Fourier-based communication system, i.e., CP-OFDM system with asingle allocated subcarrier for each UE. In particular, FIG. 5 shows the downlink of the distributed OFDM-aided DCS system.In this embodiment, the downlink communication of this system in a distributed way using a DCS is discussed. FIG. 5demonstrates how the impinging signal on each sub-DCS will be multiplied by a specific phasor, so that the received signal atthe corresponding UE, and after the summation of received samples by the UE, corresponds to the demodulated OFDM symbolallocated to that UE. It should be noted that a controller for the multicarrier communication system is not shown in FIG. 5, butthe controller, which may be the control entity 300 as shown in FIG. 3 or FIG. 4, provides the configurations for the DCS andthe UEs, thereby distributing processing tasks of multicarrier modulation and demodulation to the DCS, the UEs, and the base station, so that an overall distributed processing allows modulation and demodulation processing of the multicarrier communication system.In this disclosure, the objective of the controller for the multicarrier communication system is to:1. Allocate a sub-DCS (e.g., a first sub-DCS 320-1 shown in FIG. 5) to a UE (e.g., the first node 311 shown in FIG. 5),where each sub-DCS could have either adjacent and / or non-adjacent elements that lie within one or multiple DCSnodes. FIG. 6 shows different sub-DCSs examples where DCS elements with the same color represent a single sub- DCS. In particular, FIG. 6(a) illustrates a continious subset construction with contigous elements, and FIG. 6(b) illustrates a discrete subset construction with non-contigous elements. Notably, one sub-DCS may have elements in thetwo physically separated DCS surfaces. For example, a sub-DCS may consist of elements from the DCS surface shownin FIG.6(a) and elements from the DCS surface shown in FIG.6(b). The sub-DCS to UE allocation process could be random or following different strategies, for example: ^Sub-DCSs are allocated to guarantee equivalent link budgets between served UEs.^ Sub-DCS are allocated based on an SINR lookup table of best user and sub-DCS pairs.^ Each UE is allocated its closest sub-DCS.According to an embodiment of this disclosure, the control entity 300 may be configured to determine the sub-DCS allocation randomly, or in one of the following manners: -based on link budgets among the nodes of the first set of nodes,- based on a lookup table between the nodes of the first set of nodes and sub-DCSs of the one or more DCSs, or- based on distances between the nodes of the first set of nodes and sub-DCSs of the one or more DCSs.According to an embodiment of this disclosure, the control entity 300 is configured to determine a first sub-DCS 320-1 and atleast one first subcarrier allocated to the first node 311, wherein the first sub-DCS 320-1 comprises at least one controllablescattering element of the one or more DCS nodes 320.As shown in FIG. 3, the control entity 300 is configured to distribute the one or more processing tasks 301, 302, 303 of theplurality of processing tasks of the multicarrier modulation and demodulation to each of the first node 311, second node 312,and the first sub-DCS 320-1. In particular, the one or more processing tasks of the plurality of processing tasks of themulticarrier modulation and demodulation that are distributed for the first sub-DCS 320-1, when executed by the first sub-DCS320-1, cause the first sub-DCS 320-1 to:- scatter a first signal transmitted from the first node 311, wherein the first signal is a signal that has been processedthrough the processing tasks assigned by the control entity 300 to the first node 311 with or without a knowledgeof the at least one first subcarrier at the first node 311, while allowing the second node 312 to obtain a demodulatedsignal from the scattered first signal through the processing tasks assigned by the control entity 300 to the secondnode 312, and / or -scatter a second signal transmitted from the second node 312, wherein the second signal is a signal that has beenprocessed through the processing tasks assigned by the control entity 300 to the second node 312, so as to allowthe first node 311 to obtain a demodulated signal from the scattered second signal through the processing tasksassigned by the control entity 300 to the first node 311, with or without knowledge of the at least one first subcarrierat the first node 311.Optionally, the control entity 300 is further configured to provide a first configuration to the first sub-DCS 320-1, wherein thefirst configuration comprises a first common phasor for the first sub-DCS 320-1, and a first specific phasor for each of the controllable scattering elements of the first sub-DCS 320-1.According to an embodiment of this disclosure, the first common phasor is computed based on the one or more processingtasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the first sub- DCS 320-1. Optionally, the first common phasor and the first specific phasor are computed based on the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the first sub- DCS 320-1.According to an embodiment of this disclosure, the control entity 300 is further configured to determine the first commonphasor for the first sub-DCS 320-1 to enable the first sub-DCS 320-1 to perform the one or more processing tasks of theplurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first sub-DCS 320-1by enabling the first sub-DCS 320-1 to frequency shift an impinging signal transmitted from the first node 311 through theprocessing tasks assigned by the control entity 300 to the first node 311, and / or enabling the first sub-DCS 320-1 to frequencyshift an impinging signal transmitted from the second node 312 through the processing tasks assigned by the controller to thesecond node 312.According to an embodiment of this disclosure, the control entity 300 is further configured to determine the first specific phasorfor each of the controllable scattering elements of the first sub-DCS 320-1 to enable the first sub-DCS 320-1 to perform theone or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that areassigned for the first sub-DCS 320-1 by enabling the first sub-DCS 320-1 to beam towards the first node 311.Possibly, the control entity 300 is configured to determine the first common phasor for the first sub-DCS 320-1 based on a firstfrequency shift that is based on the at least one first subcarrier and that is allocated to the first sub-DCS 320-1. In one particular example, the control entity 300 is configured to determine a baseband frequency of one of the at least one first subcarrier as the first frequency shift.As shown in FIG. 5, there may be multiple UEs in the system. According to an embodiment of this disclosure, the UEs (i.e.,the first set of nodes) further comprise a third node 313. The control entity 300 is configured to determine a second sub-DCS320-2 and at least one second subcarrier allocated to the third node 313, wherein the second sub-DCS 320-2 comprises at leastone controllable scattering element of the one or more DCS nodes 320.The control entity 300 is configured to distribute one or more processing tasks of the plurality of processing tasks of themulticarrier modulation and demodulation to each of the third node 313, the second node 312, and the second sub-DCS 320-2, wherein the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are assigned for the second sub-DCS 320-2, when executed by the second sub-DCS 320-2, cause the second sub-DCS 320-2 to:- scatter a third signal transmitted from the third node 313, wherein the third signal is a signal that has been processedthrough the processing tasks assigned by the control entity 300 to the third node 313 with or without a knowledgeof the at least one second subcarrier at the third node 313, while allowing the second node 312 to obtain thedemodulated signal from the scattered third signal through the processing tasks assigned by the control entity 300 to the second node 312, and / or -scatter a fourth signal transmitted from the second node 312, wherein the fourth signal is a signal that has beenprocessed through the processing tasks assigned by the control entity 300 to the second node 312, so as to allowthe third node 313 to obtain a demodulated signal from the scattered fourth signal through the processing tasksassigned by the control entity 300 to the third node 313, with or without knowledge of the at least one secondsubcarrier at the third node 313.Optionally, the control entity 300 is further configured to provide a second configuration to the second sub-DCS 320-2, whereinthe second configuration comprises a second common phasor for the second sub-DCS 320-2, and a second specific phasor for each of the controllable scattering elements of the second sub-DCS 320-2. Optionally, the second common phasor is computed based on the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are assigned to the second sub-DCS 320-2. Optionally, the second common phasor and the second specific phasor are computed based on the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the second sub-DCS 320-2. Notably, the control entity 300 is configured to determine a sub-DCS allocation for the first set of nodes, wherein the sub-DCSallocation indicates that the first sub-DCS 320-1 is allocated to the first node 311; or wherein the sub-DCS allocation indicatesthat the first sub-DCS 320-1 is allocated to the first node 311 and the second sub-DCS 320-2 is allocated to the third node 313.2. In one embodiment, the subcarrier allocation may be input to the controller. The input subcarrier allocation assignssubcarrier ^^ to UE ^ for the total of ^ = 1,2, , ^ UEs. This subcarrier allocation is feasible for the proposed multi-usermulticarrier Fourier-based system hence the controller keeps and uses this subcarrier allocation.In this embodiment, the control entity 300 is further configured to determine the subcarrier allocation based on a subcarrier allocation input. In particular, the control entity 300 may be configured to receive the subcarrier allocation input from an external entity, wherein the subcarrier allocation input indicates one or more subcarriers that are allocated to one or more nodes of the first set of nodes. The control entity 300 is further configured to verify the subcarrier allocation input is feasible, and determine the sub-DCS allocation to be consistent with the subcarrier allocation input if the subcarrier allocation input is verified.3. Allocate a frequency shift to each sub-DCS. The frequency shift of each sub-DCS is related to the allocated subcarrierof the considered UE (it should be noted that in this example of implementation, a sub-DCS is allocated to at least oneUE and that each UE has a single allocated subcarrier). For example, the sub-DCS allocated frequency shift could be the same subcarrier allocated to the sub-DCS.The base station shown in FIG. 5 may be the second node 312 as shown in FIG. 3 or FIG. 4. The base station maps thetransmitted symbols into the related UE’s subcarriers and creates a multi-user CP-OFDM. The overall transmitted CP-OFDMsymbol could be thus written as follows: ^^^ where ^^^^: is the duration of the Cyclic Prefix (CP).^ ^^^^^ : is the duration of the OFDM symbol.^ ^ = ^^^ + ^^^^^ : is the duration of the overall CP-OFDM symbol.The DCS shown in FIG. 5 may be a DCS node 320 shown in FIG. 3. The DCS configuration vector of the s-th sub-DCS attime instant ^, i.e., ^^(^) ∈ ℂ^^×^, is written as follows: The DCS element-specific phasors ^^^^ ∈ ℂ^^×^ of the s-th sub-DCS are configured to beam toward the corresponding UE.This can be implemented by designing ^^as follows:^^ = ∠^^,^ + ^.The DCS common phasor ^^^^(^) of the s-th sub-DCS is configured using the s-th sub-DCS allocated frequency ^^, as follows: In the example shown in FIG.5, there are 4 UEs in the multicarrier communication system. One of the UEs may be the first node 311 as shown in FIG.3 or FIG.4.In this embodiment, it is assumed that the signal propagates from the BS to the UEs via only the DCS. The cases where directlink is present could be still covered by this embodiment where the direct links could be first filtered out. The received basebandsignal at the ^-th UE is written as follows: where ^^ corresponds to the channel gain the ^-th user experiences due to the corresponding DCS beam It is worth noting that the multiplication by ^^^^^^^^^(^) in Eq. 6 is implemented by the DCS and corresponds to a part of theFourier-based modulation process, hence, the receiver does not need to implement this multiplication thanks to the aid of theDCS. In the state of the art, the UE has to implement the multiplication by ^^^^^^^^. With the proposed novel DCS-aided design,the UE can have simplified signal processing since it does not have to implement this multiplication. According to embodimentsof this disclosure, the only processing that the UE needs to perform to complete the Fourier-based modulation process is thesummation part over the time domain. Thus, in order for the UE to demodulate the symbol ^(^) transmitted by the BS, the ^-th UE needs only to accumulate received samples during ^^^^^ samples, thus, completing the OFDM demodulation process,as follows: It is worth noting that the resulting Eq. 7 is equivalent to CP removal and to the DFT demodulation processes that the standardCP-OFDM system undergoes. In other words, by only performing a summation process over the received signal as in term1 ofEq. 7, the UE ends-up demodulating the received signal similar to the standard CP-OFDM demodulation process as depictedin term2 of Eq. 7.FIG. 7 shows an embodiment in uplink communication with a single allocated subcarrier for each UE, in particular, a CP-OFDM system with a single allocated carrier for each UE. In this embodiment, how to implement the uplink of this system ina distributed way using a DCS is explained. FIG. 7 demonstrates how all UEs transmit their information symbols on a commonfrequency, and how the superimposed received signals at the base station, after being scattered by their corresponding sub- DCS, correspond to a modulated OFDM symbol so that the BS could deploy conventional demodulation processing.It should be noted that a controller for this multicarrier communication system is not shown in FIG. 7, but the controller, whichmay be the control entity 300 as shown in FIG. 3 or FIG. 4, provides the configurations for the DCS and the communicationnodes, thereby distributing processing tasks of multicarrier modulation and demodulation to the DCS, the UEs, and the basestation, so that an overall distributed processing allows modulation and demodulation processing of the multicarrier communication system.The controller implementation is similar to the previous embodiments discussed in FIG. 5. The DCS implementation of theelement-specific phasors is also similar to the previous embodiments discussed in FIG.5.Regarding the DCS common phasor of the s-th sub-DCS, it is configured using the s-th sub-DCS allocated frequency^^and the common frequency ^^^^^^^, as follows: In uplink transmission, all UEs send their information symbols in a synchronized manner and on a predefined frequency, forexample a common frequency, denoted by ^^^^^^^, where the baseband transmitted signal from the ^-th UE is written asfollows:^^(^) = ^^^^^^^^^^^^^(^) ^ℎ^^^ 0 ≤ ^ < ^.This means that each UE transmits its information symbol over the whole duration of the overall CP-OFDM symbol ^ = ^^^ +^^^^^that will be received at the base station. This is equivalent to sending consecutive copies of the single-subcarrier symbol transmitted by the UE.It may be worth mentioning that in state-of-the art each UE ^ transmits on a different subcarrier hence signaling is needed toinform each UE of its allocated subcarrier. According to an implementation example of the design proposed in this disclosure,a default ^^^^^^^ can be used by all UEs and hence no signaling is required. In the example given in FIG. 7, ^^^^^^^ = ^^.The base station shown in FIG. 7 may be the second node 312 as shown in FIG. 3 or FIG. 4. In this example, ^^ sub-DCSs areconsidered. In this particular embodiment, only one subcarrier is allocated per user, and user ^ gets allocated subcarrier ^ andsub-DCS ^. Based on the DCS beamforming design of the s-th sub-DCS given by ^^^^,^ , , … , ^^^^,^^ that isproposed in this disclosure, it is known that the signal received at the BS from UE ^ contains only the contribution from sub-DCS ^ (the dominant contribution from UE ^ is via DCS ^ hence the contribution from other sub-DCSs and from any othernon-DCS paths can be ignored in this embodiment). The arriving signal of ^^^UE after being scattered by the corresponding sub-DCS and down-converted to the baseband is written as follows: Thus, although all UEs are transmitted on ^^^^^^^, the sub-DCSs successfully shift the signals sent by the UEs so that at theBS the signal from UE ^ is received at subcarrier ^^. This means that the UEs did not have to modulate their signals at ^^ andthanks to the DCS-aid the signal received at the BS from UE ^ is received at ^^ .^^ corresponds to the channel gain the ^ user experiences due to the corresponding DCS beam and, as explained in theembodiment shown in FIG.5, is typically given by ^^denotes the number of DCS elements within the ^^^sub-DCS.Since the UEs are sending their signals in a synchronized manner, and applying some power allocations to unify their channelgains = ^^ = ^^ ∀ ^, ^ ∈ {0,1, … ^ − 1} , the overall accumulated baseband received signal of all considered UEs at the basestation could be written as follows: The received signal form of Eq. 8 is the standard CP-OFDM signal received at the BS in the uplink. Thus, the base stationcould deploy standard techniques to demodulate the received signal and estimate the transmitted symbols.In another embodiment, this disclosure may also apply to a multi-user multicarrier Fourier-based communication system withmultiple allocated subcarriers for each UE. In the downlink communication of this system, the controller for this multicarrier communication system is objective to:1. Allocate a sub-DCS to at least one UE where each sub-DCS could have either adjacent and / or non-adjacent elementsthat lie within one or multiple DCSs, as shown in FIG.6. The sub-DCS to UE allocation process could be random or follow different strategies, as discussed in the previous embodiment with a single allocated subcarrier for each UE.2. In this embodiment, it is considered that the subcarrier allocation is input to the controller The allocated UE subcarriersare distributed uniformally across the overall transmitted OFDM subcarriers. The controller verifies the allocation ofsubcarriers to UEs. This implies verifying the distribution of the allocated subcarriers of each UE across the overall OFDM symbol. As an example, in this embodiment the controller decides to perform a new subcarrier allocation since after its verification it identifies the input allocation as an unfeasible one for the implementation of the distributed multi- user multicarrier Fourier-based system. The OFDM subcarriers are thus allocated to the different UEs by the controller.Each UE gets a sub-set of the subcarriers and the allocated subcarriers of each UE are distributed among the OFDMsubcarriers following a predefined pattern where they have an equivalent distance between each two adjacent allocated subcarriers of the same UE.. This new allocation renders the distributed multi-user multicarrier Fourier-based systemconcept feasible.3. Allocate a frequency shift to each sub-DCS. The frequency shift of each sub-DCS is selected from the set of allocatedsubcarriers to the considered UE (it should be noted that a sub-DCS is allocated to a UE and that each UE has a set ofallocated subcarriers). For example, the sub-DCS allocated frequency shift could correspond to the first, second, or third, etc. subcarrier of the UE-allocated subcarriers.In this embodiment, the new subcarrier allocation performed by the controller is given / notified to the base station. Based onthat, the BS creates a CP-OFDM signal. The created CP-OFDM symbol contains the information symbols destined for theserved UEs and that are allocated to different subcarriers. The overall base-band transmitted CP-OFDM symbols could be thus written in a standard way, as previously described in Eq.4.The DCS configuration vector of the s-th sub-DCS at time instant t, i.e., ^^(^) ∈ ℂ^^×^, is written as follows: The DCS element-specific phasors ^^^^ ∈ ℂ^^×^ of the s-th sub-DCS are configured to beam toward the corresponding UE.This can be implemented by designing ^^as follows:^^ = ∠^^,^ + ^,where ^^,^ ∈ ℂ^×^^represent the concatenated channel between the base station and the s-th UE via the s-th sub-DCS as previously explained.The DCS common phasor ^^^^(^) of the s-th sub-DCS is configured using the s-th sub-DCS allocated frequency ^^, as follows: In order for the s-th UE to extract its information symbols from its received signal, it does the following processes:1. It does ^^ summation processes where ^^ refers to the number of subcarriers allocated to the s-th UE. Each summationprocess accumulates (^ / ^^) interleaved samples from the received signal, 2. The outputs of the ^^ summations [^^^(0), ^^^(2), … , ^^^(^^ − 1)] are provided to an OFDM demodulator (e.g.,FFT) where the minimum required size of the FFT is equivalent to ^^ ≤ ^.It is worth noting that based on this disclosure, the UE does not require the knowledge of its set of allocated subcarriers Ω^while it requires the knowledge of the number of its allocated subcarriers ^^. In the uplink communication of this system, the controller for this multicarrier communication system is objective to:1. Allocate a sub-DCS to a UE where each sub-DCS could have either adjacent and / or non-adjacent elements that liewithin one or multiple DCSs, as shown in FIG.6. The sub-DCS to UE allocation process could be random or follow different strategies, as discussed in the previous embodiment with a single allocated subcarrier for each UE.2. In this embodiment, it is considered a case where the subcarrier allocation is not input to the controller. In thisembodiment, the controller performs the allocation of OFDM subcarriers to UEs since the optional input of subcarrierallocation is not present. Each UE gets a sub-set of the subcarriers and the allocated subcarriers of each UE are distributed among the OFDM subcarriers following a predefined pattern where they have an equivalent distance between each two adjacent allocated subcarriers of the same UE. In other words, the allocated UE subcarriers are distributed uniformly across the overall transmitted OFDM subcarriers. This new allocation renders the distributed multi-user multicarrier Fourier-based system concept feasible.3. Allocate a frequency shift to each sub-DCS.. For example, the sub-DCS allocated frequency shift could correspond tothe first, second, or third, etc. subcarrier of the UE-allocated subcarriers.In this embodiment, each UE constructs a ^^ size OFDM symbol where ^^ = |Ω^| refers to the number of allocatedsubcarriers to the s-th UE. Each UE transmits ^ / ^^consecutive copies of its constructed ^^size OFDM symbol. Thus, the overall baseband representation of the transmitted symbol of the s-th UE could be written as follows: where ^ ^^^(^) denotes the ^ modulo of ^.It is worth noting that UEs are sending their symbols on shared subcarriers. In other words, the subcarriers transmitted by thes-th user are ^^ with ^ ∈ [0, ^^ − 1] where only the number of transmitted subcarriers ^^ differs between UEs. Thus, the UEsdo not need to know their own subcarrier allocation mapping and the related processing is alleviated.The DCS implementation of the element-specific phasors is similar to the previous embodiment discussed in FIG. 5. Regardingthe DCS common phasor of the s-th sub-DCS, it is configured using the ^-th sub-DCS allocated frequency ^^ , asfollows: ^^ ^^^ ≤ ^ < ^ ^^ 0 ≤ ^ < ^. ^^The arriving signal of ^-th UE after being scattered by the corresponding sub-DCS and down-converted into baseband at the base station, is written as follows: where ^^ corresponds to the channel gain, assuming a frequency flat channel, that the ^-th UE experiences due to thecorresponding DCS beam ^^ denotes the number of DCS elements within the ^-th sub-DCS.The overall received signal of all UEs at the base station could be written as follows: The received signal form of Eq. 9 results in the standard CP-OFDM waveform. Thus, the base station could deploy conventionaltechniques to demodulate the received signal and estimate the transmitted symbols.In another embodiment, random frequencies may be used at the communicating nodes. This applied to any of the previouslydescribed embodiments with the difference of the frequencies used at the UE, i.e., the node implementing a simplifiedprocessing.In the previous embodiments, for simplicity and without loss of generality, the same set of frequencies have been assigned.The various corresponding sub-DCSs apply an appropriate frequency shift such as to shift the signals on the appropriatefrequencies and construct the OFDM structure. The shifted operation applied at the DCS for a transmitted signal ^^(^) =^^^^^^^^^^^^^(^) is given by by ^^^^(^^^^^^^^^^)^ and shifts the common used frequency ^^^^^^^ to the allocated one ^^.In this embodiment, a randomly used frequency (i.e., ^^,^ ∈ ℱ^) by each of the UEs is considered. For the ^-th UE, a set offrequencies ℱ^where the feasibility condition remains valid. Under these conditions, the correction applied by each of the sub-DCSs would aim at shifting each of the frequencies ^^,^ ∈ ℱ^ to the allocated one i.e. ^^. Consequently, the phasor applied bythe corresponding ^-th sub-DCS reads as ^^^^^^^^^^,^^^.It may be worth mentioning that in order for the DCS to be able to identify the proper shift, the information on the usedfrequencies at the ^-th UE becomes mandatory and can be obtained by the DCS or by the controller through signaling. Areverse communication scheme for the information exchange can also be imagined as it can be defined and imposed by the controller and provided to the UEs.FIG. 8 shows a signaling diagram for downlink communication configuration in a multicarrier communication system with asingle allocated subcarrier for each UE, according to an embodiment of this disclosure.It can be seen that the controller in the system provides configuration information to other nodes in order to distribute the signalprocessing burden between the DCS nodes and the UE.According to an embodiment of this disclosure, the control entity 300 may be configured to provide a first indication to thefirst node 311. In particular, the first indication indicates the one or more processing tasks 301 that are distributed for the firstnode 311. Although it is not shown in FIG.8, it may be understood that there may be more than one UE in the system. For instance, theEnd user shown in FIG. 8 may also be the third node 313 as shown in FIG. 5. In this case, the control entity 300 may beconfigured to provide a third indication to the third node 313, wherein the third indication indicates the one or more processingtasks that are distributed for the third node 313.According to an embodiment of this disclosure, the control entity 300 may be configured to provide a second indication to thesecond node 312. In particular, the second indication indicates the one or more processing tasks 302 that are distributed for thesecond node 312. Notably, the second indication may further comprise the subcarrier allocation.According to an embodiment of this disclosure, the control entity 300 may be configured to provide a fourth indication to theone or more DCS nodes 320, wherein the fourth indication indicates the one or more processing tasks that are distributed forthe first sub-DCS 320-1, and / or provide a fifth indication to the one or more DCS nodes 320, wherein the fifth indicationindicates the one or more processing tasks that are distributed for the second sub-DCS 320-2.Notably, the first sub-DCS 320-1 and the second sub-DCS 320-2 are not shown in FIG. 8. The DCS shown in FIG. 8 may alsobe the DCS 320 as shown in FIG. 5, which comprises the first sub-DCS 320-1 and the second sub-DCS 320-2. It may be worthfurther mentioning that although in FIG. 5, both the first sub-DCS 320-1 and the second sub-DCS 320-2 are located in the sameDCS surface, in other implementation scenario the first sub-DCS 320-1 and the second sub-DCS 320-2 may be located indifferent DCS surfaces.Optionally, at least one of the first indication, the second indication, the third indication, the fourth indication, and the fifthindication, comprises a duration of an overall symbol (T) and / or a duration of a cyclic prefix (TCP) of the multicarrier communication system.FIG. 9 shows a signaling diagram for uplink communication configuration in a multicarrier communication system with asingle allocated subcarrier for each UE, according to an embodiment of this disclosure.Similar to the downlink communication configuration, the controller in the system provides configuration information to othernodes in order to distribute the signal processing burden between the DCS nodes and the UE.As previously discussed, the control entity 300 may be configured to provide a first indication to the first node 311, whichindicates the one or more processing tasks 301 that are distributed for the first node 311. Optionally, the first indication further comprises a quantity of the subcarriers of the at least one first subcarrier that are allocated to the first node 311.According to an embodiment of this disclosure, the control entity 300 may be configured to obtain a first uplink frequency forthe first node 311 to use for transmission. Possibly, the first indication further comprises the first uplink frequency.The control entity 300 may also be configured to provide a third indication to the third node 313, which indicates the one ormore processing tasks that are distributed for the third node 313. Optionally, the third indication comprises a quantity of thesubcarriers of the at least one second subcarrier that are allocated to the third node 313.According to an embodiment of this disclosure, the control entity 300 may be configured to obtain a second uplink frequencyfor the third node 313 to use for transmission. Possibly, the third indication further comprises the second uplink frequency.Optionally, the first uplink frequency and / or the second uplink frequency are a common frequency, or randomly selected. The signalings to the DCS node 320, and to the second node 312 are similar as discussed in the embodiments shown in FIG.8.FIG. 10 shows a method 1000 for a control entity 300 for a multicarrier communication system according to this disclosure.The method 700 may be performed by the control entity 300 of FIG. 3 as disclosed above. The multicarrier communicationsystem comprises a plurality of communication nodes 310 and one or more DCS nodes 320. The plurality of communicationnodes 310 comprises a first set of nodes and a second set of nodes, the first set of nodes comprises a first node 311, and thesecond set of nodes comprises a second node 312. Each DCS comprises a plurality of controllable scattering elements.The method 1000 comprises a step 1001 of: distributing one or more processing tasks 301, 302, 303 of a plurality of processingtasks of multicarrier modulation and demodulation to each of the first node 311, the second node 312, and the one or more DCS nodes 320, so that an overall distributed processing allows modulation and demodulation processing of the multicarrier communication system.The method 1000 may further comprise actions according to the aforementioned exemplary embodiment of the control entity300. Hence, the method 1000 achieves the same advantages as the control entity 300 as disclosed above.The present disclosure further provides a computer program product comprising a program code for carrying out, whenimplemented on a processor, the method 1000 shown in FIG. 10. The computer program may be included in a computer-readable medium of the computer program product. The computer-readable medium may comprise essentially any memory, such as a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), a 15 EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), or a hard disk drive. The computer program product may further comprise actions according to the described aforementioned method 1000. Hence,the computer program product achieves the same advantages as the method 1000 and as the control entity 300.FIG. 11 shows a method 1100 for a DCS node 320 for a multicarrier communication system according to this disclosure. Themethod 1100 may be performed by the DCS node 320 of FIG. 3 as disclosed above. The multicarrier communication systemcomprises a plurality of communication nodes 310 and one or more DCS nodes 320. The plurality of communication nodes310 comprises a first set of nodes and a second set of nodes, the first set of nodes comprises a first node 311, and the secondset of nodes comprises a second node 312. Each DCS comprises a plurality of controllable scattering elements. The DCS node320 is divided into a plurality of sub-DCS, wherein each sub-DCS comprises a subset of the plurality of controllable scatteringelements in the DCS node 320. The method 1100 comprises a step 1101 of: receiving, from a control entity 300, a first configuration for a first sub-DCS 320-1 of the DCS, wherein the first configuration comprises a first common phasor for the first sub-DCS 320-1, and a first specificphasor for each of the controllable scattering elements of the first sub-DCS 320-1, wherein the first common phasor is computed based on one or more processing tasks of a plurality of processing tasks of the multicarrier modulation and demodulation thatare distributed to the first sub-DCS 320-1 by the control entity 300.The method 1100 may further comprise actions according to the aforementioned exemplary embodiment of the DCS node 320. Hence, the method 1100 achieves the same advantages as the DCS node 320 as disclosed above. The present disclosure further provides a computer program product comprising a program code for carrying out, whenimplemented on a processor, the method 1100 shown in FIG. 11. The computer program may be included in a computer-readable medium of the computer program product. The computer-readable medium may comprise essentially any memory,such as a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), a 15 EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), or a hard disk drive. The computer program product may further comprise actions according to the described aforementioned method 1100. Hence, the computer program product achieves the same advantages as the method 1100 and as the DCS node 320.FIG. 12 shows a method 1200 for a first node 311 for a multicarrier communication system according to this disclosure. Themethod 1200 may be performed by the first node 311 of FIG. 3 as disclosed above. The multicarrier communication systemcomprises a plurality of communication nodes 310 and one or more DCS nodes 320. The plurality of communication nodes310 comprises a first set of nodes and a second set of nodes, the first set of nodes comprises the first node 311, and the secondset of nodes comprises a second node 312. Each DCS comprises a plurality of controllable scattering elements.The method 1200 comprises a step 1201 of: receiving, from a control entity 300, a first indication, wherein the first indication indicates one or more processing tasks 301 of a plurality of processing tasks of the multicarrier modulation and demodulationthat are distributed for the first node 311 by the control entity 300.The method 1200 may further comprise actions according to the aforementioned exemplary embodiment of the first node 311.Hence, the method 1200 achieves the same advantages as the first node 311 as disclosed above.The present disclosure further provides a computer program product comprising a program code for carrying out, whenimplemented on a processor, the method 1200 shown in FIG. 12. The computer program may be included in a computer-readable medium of the computer program product. The computer-readable medium may comprise essentially any memory, such as a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), a 15 EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), or a hard disk drive. The computer program product may further comprise actions according to the described aforementioned method 1200. Hence,the computer program product achieves the same advantages as the method 1200 and as the first node 311.To summarize, this disclosure proposes a distributed multi-user multicarrier Fourier-based system enabled by DCS where theFourier transformation MODEM process is distributed across the UE and DCS nodes and this leads to relaxing the UEs fromsubcarrier allocation knowledge and related processing. This results in reducing UE’s signaling, UE’s power consumption, andcomputational complexities requirements. It also results in increasing the spectral efficiency of the system.The proposed approach consists of: ^Single or multiple DCSs that are controlled by a controller and that are designed to create multiple beams (e.g., bymeans of multiple sub-DCSs) with each UE being allocated a single beam (e.g., a single sub-DCS). oEach sub-DCS applies a specific frequency shift to its impinging signal.o The frequency shift allocated to a sub-DCS is related to a subcarrier selected from the subcarriers allocatedto the corresponding UE. ^A set of UEs with simplified processing such as:o In the downlink case, each UE extracts its subcarriers by first conducting a number of summations ofdifferent distributed samples of the received signal, then providing the summation outputs to the Fouriertransformation demodulator (e.g., FFT) with a size that corresponds to the number of its allocatedsubcarriers that are less or equal to the number of total allocated subcarriers at the base station level. TheUE does not need any knowledge of the frequency allocation map of its subcarriers and is relaxed from associated processing. oIn the uplink case, each UE modulates the information symbols via Fourier transformation with a size thatcorresponds to the number of its allocated subcarriers that are less than or equal to the number of totalallocated subcarriers at the base station level. The UE then sends consecutive copies of its constructed multicarrier Fourier-based symbol over a given carrier frequency. The UE does not need any knowledge ofthe frequency allocation map of its subcarriers and is relaxed from associated processing. The present disclosure has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed embodiments of the disclosure, from the studies of the drawings, this disclosure, and the independent claims. In the claims as well as in the description the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutually different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation. Furthermore, any method according to embodiments of the disclosure 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 a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), an EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), or a hard disk drive. Moreover, it is realized by the skilled person that embodiments of the control entity 300 or the first node 310 comprise the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing the solution. 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, trellis-coded modulation (TCM) encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged together for performing the solution. Especially, the processor(s) of the control entity 300 or the first node 310 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 thusrepresent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some, or all of the onesmentioned 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.

Claims

CLAIMS1. A control entity (300) for a multicarrier communication system that comprises a plurality of communication nodes(310) and one or more digitally controllable scatterer, DCS, nodes (320), wherein the plurality of communication nodes (310) comprises a first set of nodes and a second set of nodes, the first set of nodes comprises a first node (311), and the second set of nodes comprises a second node (312), wherein each DCS node (320) comprises a plurality of controllable scattering elements, and the control entity (300) is configured to: distribute one or more processing tasks (301, 302, 303) of a plurality of processing tasks of multicarrier modulation and demodulation to each of the first node (311), the second node (312), and the one or more DCS nodes (320), so that an overall distributed processing allows modulation and demodulation processing of the multicarrier communication system.

2. The control entity (300) according to claim 1, configured to:determine a first sub-DCS (320-1) and at least one first subcarrier allocated to the first node (311), wherein the first sub-DCS (320-1) comprises at least one controllable scattering element of the one or more DCS nodes (320); and distribute the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation to each of the first node (311), second node (312), and the first sub-DCS (320-1), wherein the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first sub-DCS (320-1), when executed by the first sub-DCS (320-1), cause the first sub-DCS (320- 1) to: scatter a first signal transmitted from the first node (311), wherein the first signal is a signal that has beenprocessed through the processing tasks assigned by the control entity (300) to the first node (311) with or without a knowledge of the at least one first subcarrier at the first node (311), while allowing the second node (312) to obtain a demodulated signal from the scattered first signal through the processing tasks assigned bythe control entity (300) to the second node (312), and / or scatter a second signal transmitted from the second node (312), wherein the second signal is a signal that has been processed through the processing tasks assigned by the control entity (300) to the second node (312), so as to allow the first node (311) to obtain a demodulated signal from the scattered second signal through the processing tasks assigned by the control entity (300) to the first node (311), with or without knowledge of the at least one first subcarrier at the first node (311).

3. The control entity (300) according to claim 2, configured to:provide a first configuration to the first sub-DCS (320-1), wherein the first configuration comprises a first common phasor for the first sub-DCS (320-1), and a first specific phasor for each of the controllable scattering elements of the first sub-DCS (320-1).

4. The control entity (300) according to claim 3, wherein the first common phasor is computed based on the one or moreprocessing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to thefirst sub-DCS (320-1); or wherein the first common phasor and the first specific phasor are computed based on the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the first sub- DCS (320-1).

5. The control entity (300) according to claim 4, configured to:determine the first common phasor for the first sub-DCS (320-1) to enable the first sub-DCS (320-1) to perform the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first sub-DCS (320-1) by enabling the first sub-DCS (320-1) to frequency shift an impinging signal transmitted from the first node (311) through the processing tasks assigned by the control entity (300) to the first node (311), and / or enabling the first sub-DCS (320-1) to frequency shift an impinging signal transmitted from the second node (312) through the processing tasks assigned by the controller to the second node (312); and determine the first specific phasor for each of the controllable scattering elements of the first sub-DCS (320-1) to enablethe first sub-DCS (320-1) to perform the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first sub-DCS (320-1) by enabling the first sub-DCS (320-1) to beam towards the first node (311).

6. The control entity (300) according to claim 4 or 5, configured to:determine the first common phasor for the first sub-DCS (320-1) based on a first frequency shift that is based on the at least one first subcarrier and that is allocated to the first sub-DCS (320-1).

7. The control entity (300) according to claim 6, configured to:determine a baseband frequency of one of the at least one first subcarrier as the first frequency shift.

8. The control entity (300) according to one of the claims 1 to 7, wherein the first set of nodes further comprises a third node (313), and the control entity (300) is configured to: determine a second sub-DCS (320-2) and at least one second subcarrier allocated to the third node (313), wherein the second sub-DCS (320-2) comprises at least one controllable scattering element of the one or more DCS nodes (320); and distribute one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation to each of the third node (313), the second node (312), and the second sub-DCS (320-2), wherein the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the second sub-DCS (320-2), when executed by the second sub-DCS (320-2), cause the second sub-DCS (320-2) to: scatter a third signal transmitted from the third node (313), wherein the third signal is a signal that has been processed through the processing tasks assigned by the control entity (300) to the third node (313) with or without a knowledge of the at least one second subcarrier at the third node (313), while allowing the second node (312) to obtain the demodulated signal from the scattered third signal through the processing tasks assigned by the control entity (300) to the second node (312), and / or scatter a fourth signal transmitted from the second node (312), wherein the fourth signal is a signal that hasbeen processed through the processing tasks assigned by the control entity (300) to the second node (312), so as to allow the third node (313) to obtain a demodulated signal from the scattered fourth signal through the processing tasks assigned by the control entity (300) to the third node (313), with or without knowledge of the at least one second subcarrier at the third node (313).

9. The control entity (300) according to claim 8, configured to:provide a second configuration to the second sub-DCS (320-2), wherein the second configuration comprises a second common phasor for the second sub-DCS (320-2), and a second specific phasor for each of the controllable scattering elements of the second sub-DCS (320-2).

10. The control entity (300) according to claim 9, wherein the second common phasor is computed based on the one ormore processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the second sub-DCS (320-2); or wherein the second common phasor and the second specific phasor are computed based on the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the second sub-DCS (320-2).

11. The control entity (300) according to one of the claims 2 to 10, configured to:determine a sub-DCS allocation for the first set of nodes, wherein the sub-DCS allocation indicates that the first sub- DCS (320-1) is allocated to the first node (311); or wherein the sub-DCS allocation indicates that the first sub-DCS(320-1) is allocated to the first node (311) and the second sub-DCS (320-2) is allocated to the third node (313).

12. The control entity (300) according to one of the claims 2 to 11, configured to:determine a subcarrier allocation for the first set of nodes, wherein the subcarrier allocation indicates that the at least one first subcarrier is allocated to the first node (311); or wherein the subcarrier allocation indicates that the at least one first subcarrier is allocated to the first node (311) and the at least one second subcarrier is allocated to the third node (313).

13. The control entity (300) according to claim 12, configured to:determine the subcarrier allocation based on a predefined pattern, or based on a subcarrier allocation input.

14. The control entity (300) according to claim 13, wherein the predefined pattern of each node of the first set of nodesindicates to distribute the allocated subcarriers of each node of the first set of nodes uniformly across all subcarriers of themultiuser multicarrier communication system.

15. The control entity (300) according to claim 13, configured to:receive the subcarrier allocation input from an external entity, wherein the subcarrier allocation input indicates one or more subcarriers that are allocated to one or more nodes of the first set of nodes, verify the subcarrier allocation input is feasible, and determine the sub-DCS allocation to be consistent with the subcarrier allocation input if the subcarrier allocation inputis verified.

16. The control entity (300) according to claim 11 or one of the claims 12 to 15 when depending on claim 11, configuredto: determine the sub-DCS allocation randomly, or in one of the following manners: -based on link budgets among the nodes of the first set of nodes,- based on a lookup table between the nodes of the first set of nodes and sub-DCSs of the one or more DCSs,or -based on distances between the nodes of the first set of nodes and sub-DCSs of the one or more DCSs.

17. The control entity (300) according to one of the claims 1 to 17, configured to: provide a first indication to the first node (311), wherein the first indication indicates the one or more processing tasks (301) that are distributed for the first node (311), and / or provide a second indication to the second node (312), wherein the second indication indicates the one or more processing tasks (302) that are distributed for the second node (312), and / orprovide a third indication to the third node (313), wherein the third indication indicates the one or more processing tasks that are distributed for the third node (313), and / or provide a fourth indication to the one or more DCS nodes (320), wherein the fourth indication indicates the one or more processing tasks that are distributed for the first sub-DCS (320-1), and / or provide a fifth indication to the one or more DCS nodes (320), wherein the fifth indication indicates the one or more processing tasks that are distributed for the second sub-DCS (320-2).

18. The control entity (300) according to claim 17, wherein the first indication comprises a quantity of the subcarriers ofthe at least one first subcarrier that are allocated to the first node (311), and / or the third indication comprises a quantity of the subcarriers of the at least one second subcarrier that are allocated to the third node (313).

19. The control entity (300) according to one of the claims 1 to 18, configured to: obtain a first uplink frequency for the first node (311) to use for transmission; and / or obtain a second uplink frequency for the third node (313) to use for transmission.

20. The control entity (300) according to claim 17 or 18, and claim 19, wherein the first indication further comprises the first uplink frequency, and / or the third indication further comprises the second uplink frequency.

21. The control entity (300) according to claim 19 or 20, wherein the first uplink frequency and / or the second uplinkfrequency are a common frequency, or randomly selected.

22. The control entity (300) according to one of the claims 17 to 21, wherein at least one of the first indication, the secondindication, the third indication, the fourth indication, and the fifth indication, comprises a duration of an overall symbol and / or a duration of a cyclic prefix of the multicarrier communication system.

23. The control entity (300) according to one of the claims 17 to 22, wherein the second indication further comprises thesubcarrier allocation.

24. A digitally controllable scatterer, DCS, node (320), for a multicarrier communication system comprising a plurality ofcommunication nodes (310), wherein the plurality of communication nodes (310) comprises a first set of nodes and a secondset of nodes, the first set of nodes comprises a first node (311), and the second set of nodes comprises a second node (312), wherein the DCS node (320) comprises a plurality of controllable scattering elements, wherein the DCS node (320) is divided into a plurality of sub-DCS, wherein each sub-DCS comprises a subset of the plurality of controllable scattering elements in the DCS node (320), and the DCS node (320) is configured to: receive, from a control entity (300), a first configuration for a first sub-DCS (320-1) of the DCS node (320), wherein the first configuration comprises a first common phasor for the first sub-DCS (320-1), and a first specific phasor for each of the controllable scattering elements of the first sub-DCS (320-1), wherein the first common phasor is computed based on one or more processing tasks of a plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the first sub-DCS (320-1) by the control entity (300).

25. The DCS node (320) according to claim 24, wherein the first sub-DCS (320-1) is configured to:frequency shift an impinging signal transmitted from the first node (311), and / or frequency shift an impinging signal transmitted from the second node (312), based on the first common phasor of the first sub-DCS (320-1); and scatter an impinging signal towards the first node (311) based on the first specific phasor of each of the controllable scattering elements of the first sub-DCS (320-1).

26. The DSC node (320) according to claim 24 or 25, wherein the first common phasor indicates a first frequency shift thatis provided to the first sub-DCS (320-1).

27. The DSC node (320) according to claim 26, wherein the first frequency shift is a baseband frequency of one of at leastone first subcarrier that is allocated to the first node (311).

28. The DCS node (320) according to one of the claims 24 to 27, wherein the first set of nodes further comprises a thirdnode (313), and the DCS node (320) is configured to: receive, from the control entity (300), a second configuration for a second sub-DCS (320-2), wherein the second configuration comprises a second common phasor for the second sub-DCS (320-2), and a second specific phasor for each of the controllable scattering elements of the second sub-DCS (320-2), wherein the second common phasor iscomputed based on the one or more processing tasks of the plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the second sub-DCS (320-2) by the control entity (300).

29. The DCS node (320) according to one of the claims 24 to 28, configured to:receive a sub-DCS allocation configuration from the control entity (300), wherein the sub-DCS allocation configuration indicates that the first sub-DCS (320-1) is allocated to the first node (311), and / or the second sub-DCS (320-2) is allocated to the third node (313).

30. The DCS node (320) according to one of the claims 24 to 29, wherein the controllable scattering elements comprisedin each sub-DCS are adjacent and / or non-adjacent.

31. The DSC node (320) according to one of the claims 24 to 30, configured to:receive a fourth indication from the control entity (300), wherein the fourth indication indicates the one or more processing tasks that are distributed to the first sub-DCS (320-1), and / or receive a fifth indication from the control entity (300), wherein the fifth indication indicates the one or more processing tasks that are distributed to the second sub-DCS (320-2).

32. A first node (311), for a multicarrier communication system that comprises a plurality of communication nodes (310),and one or more digitally controllable scatterer, DCS, nodes (320), wherein the plurality of communication nodes (310) comprises a first set of nodes and a second set of nodes, the first set of nodes comprises the first node (311), and the second set of nodes comprises a second node (312), wherein each DCS node (320) comprises a plurality of controllable scatteringelements, and the first node (311) is configured to:receive, from a control entity (300), a first indication, wherein the first indication indicates one or more processing tasks (301) of a plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first node (311) by the control entity (300).

33. The first node (311) according to claim 32, wherein the one or more processing tasks comprise a summation process.

34. The first node (311) according to claim 33, wherein the first indication further comprises a duration of an overall symboland / or a duration of a cyclic prefix of the multicarrier communication system, and the first node (311) is configured to: receive, from the second node (312), at least one signal; and perform a summation process on received samples of the at least one signal, based on the duration of the overall symbol and / or the duration of the cyclic prefix.

35. The first node (311) according to claim 34, configured to:obtain a demodulated signal by inputting an output of the summation process into a Fourier transformation demodulator36. The first node (311) according to one of the claims 32 to 35, wherein the first indication further comprises a quantityM that indicates a quantity of subcarriers that is allocated to the first node (311), M being a positive integer.

37. The first node (311) according to claim 36 and claim 34, when M is equal to 1, the first node (311) is configured to:perform the summation process by accumulating the received samples of the at least one signal over the duration of the overall symbol minus the duration of the cyclic prefix.

38. The first node (311) according to claim 36 and claim 34, when M is greater than or equal to 2, the first node (311) isconfigured to: perform the summation process by computing one or more summations wherein each summation is generated by accumulating interleaved received samples of the at least one signal.

39. The first node (311) according to claims 38 and 35, configured to:obtain the demodulated signal by inputting the one or more summations into the Fourier transformation demodulator.

40. The first node (311) according to claim 39, wherein the summation process is performed by computing M summationsand the demodulated signal is obtained by inputting the M summations into the Fourier transformation demodulator, wherein a minimum required size of the Fourier transformation demodulator is equivalent to M.

41. The first node (311) according to one of the claims 34 to 40, wherein the first indication further comprises a first uplinkfrequency for transmission, and the first node (311) is configured to: transmit a signal using the first uplink frequency over the duration of the overall symbol.

42. The first node (311) according to claim 41, wherein the first uplink frequency is preconfigured in the first node (311),or provided by the control entity (300).

43. The first node (311) according to claim 41 or 42, configured to:construct the signal based on the quantity M, wherein the signal comprises an M size orthogonal frequency-division multiplexing, OFDM, symbol; and transmit a plurality of consecutive copies of the OFDM symbol using the first uplink frequency over the duration of the overall symbol.

44. A wireless communication system comprising a control entity (300) according to one of the claims 1 to 24, one or moredigitally controllable scatterer, DCS, nodes (320), each DCS node (320) according to one of the claims 25 to 31, and a plurality of communication nodes (310) comprising a first set of nodes and a second set of nodes, the first set of nodes comprises the first node (311) according to one of the claims 32 to 43, and the second set of nodes comprises a second node (312).

45. A method for a multicarrier communication system that comprises a plurality of communication nodes (310) and oneor more digitally controllable scatterer, DCS, nodes (320), wherein the plurality of communication nodes (310) comprises a first set of nodes and a second set of nodes, the first set of nodes comprises a first node (311), and the second set of nodes comprises a second node (312), wherein each DCS comprises a plurality of controllable scattering elements, the method being performed by a control entity (300) and comprising:distributing one or more processing tasks (301, 302, 303) of a plurality of processing tasks of multicarrier modulation and demodulation to each of the first node (311), the second node (312), and the one or more DCS nodes (320), so that an overall distributed processing allows modulation and demodulation processing of the multicarrier communication system.

46. A method for a multicarrier communication system that comprises a plurality of communication nodes (310), whereinthe plurality of communication nodes (310) comprises a first set of nodes and a second set of nodes, the first set of nodescomprises a first node (311), and the second set of nodes comprises a second node (312), the method being performed by a digitally controllable scatterer, DCS, node (320), comprising a plurality of controllable scattering elements, wherein the DCS node (320) is divided into a plurality of sub-DCS, wherein each sub-DCS comprises a subset of the plurality of controllable scattering elements in the DCS node (320), and the method comprising: receiving, from a control entity (300), a first configuration for a first sub-DCS (320-1) of the DCS, wherein the first configuration comprises a first common phasor for the first sub-DCS (320-1), and a first specific phasor for each of the controllable scattering elements of the first sub-DCS (320-1), wherein the first common phasor is computed based on one or more processing tasks of a plurality of processing tasks of the multicarrier modulation and demodulation that are distributed to the first sub-DCS (320-1) by the control entity (300).

47. A method for a multicarrier communication system that comprises a plurality of communication nodes (310) and oneor more digitally controllable scatterer, DCS, nodes (320), wherein the plurality of communication nodes (310) comprises a first set of nodes and a second set of nodes, the first set of nodes comprises the first node (311), and the second set of nodes comprises a second node (312), wherein each DCS node (320) comprises a plurality of controllable scattering elements, themethod being performed by the first node (311) and comprising:receiving, from a control entity (300), a first indication, wherein the first indication indicates one or more processing tasks (301) of a plurality of processing tasks of the multicarrier modulation and demodulation that are distributed for the first node (311) by the control entity (300).

48. A computer program comprising instructions which, when the program is executed by a computer, causes the computerto perform the method according to one of the claims 45 to 47.

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