Method and apparatus for downlink multi-user using DFT-S-OFDM waveforms

Abstract

A method performed by at least one processor of a network node operating in a wireless communication network includes receiving data associated with a plurality of users. The method further includes performing a Discrete Fourier Transform (DFT) transform on the data associated with the plurality of users by a DFT coder. The method further includes performing subcarrier mapping on an output of the DFT coder by a subcarrier mapper to map an output of the DFT coder to a set of subcarriers. The method further includes performing an Inverse DFT (IDFT) on an output of the subcarrier mapper. The method further includes transmitting the output of the IDFT as a DFT-spread optical frequency division multiplexed (DFT-s-OFDM) signal over the wireless communication network.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. patent application Ser. No. 63 / 393,475, filed July 29, 2022, the disclosure of which is incorporated by reference in its entirety herein.

[0002] The present disclosure relates generally to communication systems, and more particularly, to a method and apparatus for downlink multi-user using DFT-s-OFDM waveforms. [Background technology]

[0003] Discrete Fourier Transform (DFT) spread optical frequency division multiplexing (DFT-s-OFDM) is a variant of OFDM in which data symbols undergo DFT precoding before being mapped to the assigned subcarriers. DFT-s-OFDM is used in the uplink of 5G New Radio (NR) (38.211) and LTE (36.211). In the downlink, only OFDM is used. From the UE's perspective, in the uplink direction, all data symbols within one DFT-s-OFDM symbol are transmitted to a single receiver (e.g., gNB). However, in the downlink direction, the gNB schedules data symbols to multiple users within one DFT symbol.

[0004] The biggest advantage of DFT-s-OFDM compared to OFDM is that the use of DFT-s-OFDM results in a lower peak-to-average power ratio (PAPR). The lower PAPR allows the power amplifier to operate in the linear region, which results in higher energy efficiency. Therefore, DFT-s-OFDM is likely to be considered for downlink transmission of 5G+ or 6G communications, especially at higher carrier frequencies. To maintain a low PAPR, one DFT block is generally used, and the signal at the output of the DFT block before mapping to the subcarriers is not disturbed. When DFT-s-OFDM is used, multiple users can be multiplexed in the time domain over multiple DFT-s-OFDM symbols. In particular, DFT-s-OFDM limits the scheduling of one user over one DFT-s-OFDM symbol. This limitation reduces the scheduling efficiency.

[0005] Improvements are presented herein that may also be applicable to other multi-access technologies and telecommunications standards that use these technologies. Summary of the Invention [Means for solving the problem]

[0006] The following presents a simplified summary of one or more embodiments of the present disclosure in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all possible embodiments, and is not intended to identify key or critical elements of all embodiments or to delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments of the present disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0007] A method, apparatus, and non-transitory computer-readable medium for downlink multi-user using DFT-s-OFDM waveforms are disclosed by the present disclosure.

[0008] According to an exemplary embodiment, a method performed by at least one processor of a network node operating in a wireless communication network includes receiving data associated with a plurality of users. The method further includes performing a discrete Fourier transform (DFT) transform on the data associated with the plurality of users by a DFT coder. The method further includes performing subcarrier mapping on an output of the DFT coder by a subcarrier mapper to map an output of the DFT coder to a set of subcarriers. The method further includes performing an inverse DFT (IDFT) on an output of the subcarrier mapper. The method further includes transmitting the output of the IDFT as a DFT-spread optical frequency division multiplexed (DFT-s-OFDM) signal over the wireless communication network.

[0009] According to an exemplary embodiment, a network node operating in a wireless communication network includes at least one memory configured to store computer program code and at least one processor configured to access the at least one memory and operate as instructed by the computer program code. The computer program code includes a receiving code configured to cause the at least one processor to receive data associated with a plurality of users. The computer program code further includes a first executable code configured to cause the at least one processor to perform a DFT transform on the data associated with the plurality of users by a discrete Fourier transform (DFT) coder. The computer program code further includes a second executable code configured to cause the at least one processor to perform subcarrier mapping on an output of the DFT coder by a subcarrier mapper, the subcarrier mapping mapping an output of the DFT coder to a set of subcarriers. The computer program code further includes a third executable code configured to cause the at least one processor to perform an inverse DFT (IDFT) on an output of the subcarrier mapper. The computer program code further includes a transmitting code configured to cause the at least one processor to transmit an output of the IDFT as a DFT-spread optical frequency division multiplexed (DFT-s-OFDM) signal over a wireless communication network.

[0010] According to an exemplary embodiment, a non-transitory computer-readable medium having stored therein instructions that, when executed by a processor in a network node operating in a wireless communication network, causes the network node to perform a method including receiving data associated with a plurality of users. The method further includes performing a Discrete Fourier Transform (DFT) transform on the data associated with the plurality of users by a DFT coder. The method further includes performing subcarrier mapping on an output of the DFT coder by a subcarrier mapper, mapping an output of the DFT coder to a set of subcarriers. The method further includes performing an Inverse DFT (IDFT) on an output of the subcarrier mapper. The method further includes transmitting the output of the IDFT as a DFT-spread optical frequency division multiplexed (DFT-s-OFDM) signal over the wireless communication network.

[0011] Additional embodiments are set forth in the description which follows, and in part will be apparent from the description and / or may be learned by practice of presented embodiments of the present disclosure. [Brief description of the drawings]

[0012] The above and other aspects, features, and aspects of embodiments of the present disclosure will become apparent from the following description taken in conjunction with the accompanying drawings.

[0013] [Figure 1] FIG. 2 is a diagram of an exemplary network device in accordance with various embodiments of the present disclosure. [Diagram 2] 1 is a schematic diagram of an exemplary wireless communication system in accordance with various embodiments of the present disclosure. [Diagram 3] 1 is an exemplary DFT-s-OFDM transceiver in accordance with various embodiments of the present disclosure. [Figure 4] 1 is an exemplary DFT-s-OFDM transmitter in accordance with various embodiments of the present disclosure. [Diagram 5] 1 is an exemplary DFT-s-OFDM transmitter in accordance with various embodiments of the present disclosure. [Figure 6]1 illustrates an example of CCE mapping to pre-DFT resource blocks in accordance with various embodiments of the present disclosure. [Figure 7] 1 illustrates an example of CCE mapping to pre-DFT resource blocks in accordance with various embodiments of the present disclosure. [Figure 8] 1 shows an exemplary flow chart of one embodiment of a process for multiplexing data of multiple users onto a DFT-s-OFDM signal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The following detailed description of the exemplary embodiments refers to the accompanying drawings, in which the same reference numbers in different drawings may identify the same or similar elements.

[0015] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the implementation to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the implementations. Moreover, one or more features or components of one embodiment may be incorporated or combined with another embodiment (or one or more features of another embodiment). Furthermore, in the flowcharts and descriptions of operations provided below, it is understood that one or more operations may be omitted, one or more operations may be added, one or more operations may be performed simultaneously (at least in part), and the order of one or more operations may be interchanged.

[0016] It will be apparent that the systems and / or methods described herein may be implemented in various forms of hardware, firmware, or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not intended to limit the implementation. Thus, the operation and behavior of the systems and / or methods are described herein without reference to specific software code, and it will be understood that software and hardware can be designed to implement the systems and / or methods based on the description herein.

[0017] Although particular combinations of features are recited in the claims and / or disclosed herein, these combinations are not intended to limit the disclosure of possible implementations. Indeed, many of these features may be combined in ways not specifically recited in the claims and / or disclosed in the specification. Although each dependent claim listed below may depend directly on only one claim, the disclosure of possible implementations includes each dependent claim in combination with every other claim in the claim set.

[0018] No element, act, or instruction used herein should be construed as critical or essential unless expressly stated as such. Also, as used herein, the articles "a" and "an" are intended to include one or more things and may be used interchangeably with "one or more." When only one thing is intended, the term "one" or similar terminology is used. Also, as used herein, "has," "have," "having," "including," "has" and "has more." Terms such as "include," "including," and the like are intended to be open-ended terms. Additionally, the phrase "based on" is intended to mean "based at least in part on," unless otherwise specified. Additionally, phrases such as "at least one of [A] and [B]" or "at least one of [A] or [B]" should be understood to include only A, only B, or both A and B.

[0019] Throughout this specification, reference to "one embodiment," "an embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with the illustrated embodiment is included in at least one embodiment of the solution. Thus, the phrases "in one embodiment," "in an embodiment," and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0020] Moreover, the described features, advantages, and characteristics of the present disclosure may be combined in any suitable manner in one or more embodiments. In light of the description herein, one skilled in the art will recognize that the present disclosure can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the present disclosure.

[0021] The embodiments of the present disclosure relate to multiplexing data symbols targeted to multiple users before a DFT precoder. The embodiments of the present disclosure provide the highly advantageous feature of keeping the PAPR low while allowing multi-user scheduling in one DFT-s-OFDM symbol. The embodiments of the present disclosure also provide higher energy efficiency and also multi-user scheduling flexibility resulting in higher throughput and / or spectral efficiency.

[0022] Device 100 may correspond to any type of known computer, server, or data processing device. For example, device 100 may include a processor, a personal computer (PC), a printed circuit board (PCB) including a computing device, a minicomputer, a mainframe computer, a microcomputer, a telephone computing device, a wired / wireless computing device (e.g., a smart phone, a personal digital assistant (PDA)), a laptop, a tablet, a smart device, or any other similarly functional device.

[0023] In some embodiments, as shown in FIG. 1, the device 100 may include a set of components, such as a processor 120, a memory 130, a storage component 140, an input component 150, an output component 160, and a communication interface 170.

[0024] Bus 110 includes one or more components that enable communication between a set of components of device 100. For example, bus 110 may be a communication bus, a crossover bar, a network, etc. Although bus 110 is illustrated in FIG. 1 as a single line, bus 110 may be implemented using multiple (two or more) connections between a set of components of device 100. This disclosure is not limited in this respect.

[0025] Device 100 may include one or more processors, such as processor 120. Processor 120 may be implemented in hardware, firmware, and / or a combination of hardware and software. For example, processor 120 may be a central processing unit. The processor 120 may include a central processing unit (CPU), a graphics processing unit (GPU), an accelerated processing unit (APU), a microprocessor, a microcontroller, a digital signal processor (DSP), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a general-purpose single-chip or multi-chip processor, or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. The processor 120 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some embodiments, certain processes and methods may be performed by circuitry specific to a given function.

[0026] The processor 120 may control the overall operation of the device 100 and / or a set of components of the device 100 (eg, memory 130, storage components 140, input components 150, output components 160, communication interface 170).

[0027] Device 100 may further include memory 130. In some embodiments, memory 130 may include random-access memory (RAM), read only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic memory, optical memory, and / or another type of dynamic or static storage device. Memory 130 may store information and / or instructions for use (e.g., execution) by processor 120.

[0028] Storage component 140 of device 100 can store information and / or computer-readable instructions and / or code related to the operation and use of device 100. For example, storage component 140 can include a hard disk (e.g., a magnetic disk, optical disk, magneto-optical disk, and / or solid-state disk), a compact disc (CD), a digital versatile disc (DVD), a universal serial bus (USB) flash drive, a Personal Computer Memory Card International Association (PCMCIA) card, a floppy disk, a cartridge, a magnetic tape, and / or another type of non-transitory computer-readable medium along with a corresponding drive.

[0029] Device 100 may further include input component 150. Input component 150 may include one or more components that enable device 100 to receive information via user input, etc. (e.g., a touch screen, a keyboard, a keypad, a mouse, a stylus, a button, a switch, a microphone, a camera, etc.). Alternatively or additionally, input component 150 may include sensors for sensing information (e.g., a global positioning system (GPS) component, an accelerometer, a gyroscope, an actuator, etc.).

[0030] Output component 160 of device 100 may be one or more components capable of providing output information from device 100 (e.g., a display, LCD The display may include a liquid crystal display (LCD), a light-emitting diode (LED), an organic light emitting diode (OLED), a tactile feedback device, a speaker, etc.

[0031] The device 100 may further include a communication interface 170. The communication interface 170 may include a receiver component, a transmitter component, and / or a transceiver component. The communication interface 170 may enable the device 100 to establish a connection and / or transfer a communication with another device (e.g., a server, another device). The communication may be effected via a wired connection, a wireless connection, or a combination of wired and wireless connections. The communication interface 170 may enable the device 100 to receive information from another device and / or provide information to another device. In some embodiments, communication interface 170 may provide communication with another device over a network, such as a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a private network, an ad-hoc network, an intranet, the Internet, an optical fiber-based network, a cellular network (e.g., a fifth generation (5G) network, a long-term evolution (LTE) network, a third generation (3G) network, a code division multiple access (CDMA) network, etc.), a public land mobile network (PLMN), a telephone network (e.g., a Public Switched Telephone Network (PSTN)), etc., and / or a combination of these or other types of networks. Alternatively or additionally, the communication interface 170 may provide communication with another device via a device-to-device (D2D) communication link, such as FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi, LTE, 5G, etc.In other embodiments, communication interface 170 may include an Ethernet interface, an optical interface, a coaxial interface, an infrared interface, a radio frequency (RF) interface, or the like.

[0032] The device 100 can perform one or more processes described herein. The device 100 can perform operations based on the processor 120 executing computer-readable instructions and / or code, which may be stored by a non-transitory computer-readable medium, such as the memory 130 and / or the storage component 140. The computer-readable medium may refer to a non-transitory memory device. The memory device may include memory space within a single physical storage device and / or memory space distributed across multiple physical storage devices.

[0033] Computer readable instructions and / or code may be loaded into memory 130 and / or storage component 140 from another computer readable medium or from another device via communications interface 170. The computer readable instructions and / or code stored in memory 130 and / or storage component 140, when or if executed by processor 120, can cause device 100 to perform one or more processes described herein.

[0034] Alternatively, or in addition, hardwired circuitry may be used in place of, or in combination with, software instructions to implement one or more of the processes described herein. Thus, the embodiments described herein are not limited to any specific combination of hardware circuitry and software.

[0035] The number and arrangement of components shown in Figure 1 are provided as an example. In practice, there may be additional, fewer, different, or differently arranged components than those shown in Figure 1. Furthermore, two or more of the components shown in Figure 1 may be implemented within a single component, or a single component shown in Figure 1 may be implemented as multiple distributed components. Alternatively, or in addition, a set of components shown in Figure 1 may perform one or more functions described as being performed by another set of components shown in Figure 1.

[0036] 2 illustrates an example of a wireless communication system in accordance with various embodiments of the present disclosure. The wireless communication system 200 (which may also be referred to as a wireless wide area network (WWAN)) may include one or more user equipment (UE) 210, one or more base stations 220, at least one transport network 230, and at least one core network 240. The device 100 (FIG. 1) may be incorporated into the UE 210 or the base station 220.

[0037] One or more UEs 210 can access at least one core network 240 and / or IP services 250 via a connection to one or more base stations 220 by the RAN domain 224 and through at least one transport network 230. Examples of UEs 210 can include a mobile phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system (GPS), a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similarly functioning device. Some of the one or more UEs 210 may be referred to as Internet-of-Things (IoT) devices (e.g., a parking meter, a gas pump, a toaster, a vehicle, a heart monitor, etc.). One or more UEs 210 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a radio unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile agent, a client, or some other suitable terminology.

[0038] One or more base stations 220 can wirelessly communicate with one or more UEs 210 via the RAN domain 224. Each base station of the one or more base stations 220 can provide communication coverage to one or more UEs 210 located within the geographic coverage area of ​​that base station 220. In some embodiments, as shown in FIG. 2, a base station 220 can transmit one or more beamformed signals to one or more UEs 210 in one or more transmit directions. The one or more UEs 210 can receive the beamformed signals from the base station 220 in one or more receive directions. Alternatively or additionally, the one or more UEs 210 can transmit beamformed signals to the base station 220 in one or more transmit directions. The base station 220 can receive the beamformed signals from the one or more UEs 210 in one or more receive directions.

[0039] The one or more base stations 220 may include macro cells (e.g., high-power cellular base stations) and / or small cells (e.g., low-power cellular base stations). The base station 220, whether a macrocell or a large cell, may include and / or be referred to as an access point (AP), an evolved (or evolved universal terrestrial radio access network (E-UTRAN)) Node B (eNB), a next generation Node B (gNB), or any other type of base station known to one skilled in the art.

[0040] The one or more base stations 220 may be configured to interface (e.g., establish connections, transfer data, etc.) with at least one core network 240 via at least one transport network 230. In addition to other functions, the one or more base stations 220 may perform one or more of the following functions: forwarding data (e.g., uplink data) received from one or more UEs 210 to the at least one core network 240 via the at least one transport network 230; forwarding data (e.g., downlink data) received from the at least one core network 240 to the one or more UEs 210 via the at least one transport network 230.

[0041] The transport network 230 may transport data (e.g., uplink data, downlink data) and / or signaling between the RAN domain 224 and the CN domain 244. For example, the transport network 230 may provide one or more backhaul links between one or more base stations 220 and at least one core network 240. The backhaul links may be wired or wireless.

[0042] The core network 240 may be configured to provide one or more services (e.g., enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), massive machine type communications (mMTC), etc.) to one or more UEs 210 connected to the RAN domain 224 via the TN domain 234. Alternatively or additionally, the core network 240 may serve as an entry point for IP services 250. The IP services 250 may include the Internet, an intranet, an IP multimedia subsystem (IMS), streaming services (e.g., video, audio, games, etc.), and / or other IP services.

[0043] FIG. 3 shows one embodiment of a baseband block diagram of a DFT-s-OFDM transceiver. The transceiver may include a transmit circuit 300A and a receive circuit 300B. The transmit circuit 300A and the receive circuit 300B may be located in different network nodes. For example, the transmit circuit 300A may be included in a first base station, while the receive circuit 300B may be included in a second base station or another UE. The transmit circuit 300A transmits M data symbols d0, ..., d M-1The DFT precoder 302A may include a DFT precoder 302A that performs a DFT operation on M. The data symbols may be user data of multiple users, control data, or a combination of both. The output of the DFT precoder 302A may then be input to a subcarrier mapper (SM) 304A, which may map the DFT output to a set of subcarriers. The output of the SM 304A may be provided to an IDFT 306A and then to a CP 308A for adding a cyclic prefix (CP). After adding the CP, the DFT-s-OFDM signal may be further processed and transmitted. The size of the IDFT block may be greater than M.

[0044] In the receiver 300B, the CP is first removed by the CP removal 308B, and the DFT is performed on the received signal by the DFT 302B. The subcarrier demapper (SdM) 304B can select M outputs of the DFT corresponding to the subcarriers used. The selected outputs may then be processed by the IDFT block 306B. Both the transmit circuit 300A and the receive circuit can include additional blocks, such as an equalizer, a channel estimator, etc. In the presence of a channel and / or noise, the symbols at the output of the IDFT block in the receiver can be estimates of the transmitted symbols.

[0045] In some embodiments, data symbols can be transmitted to two or more target receivers in one DFT-s-OFDM symbol. Data symbols targeted to different users can be multiplexed before a DFT precoder at a transmitter, such as DFT precoder 402 of transmitter 400 of FIG. 4 or DFT precoder 502 of transmitter 500 of FIG. 5. In this example, data symbols d0, ..., d M-1 , may be data symbols scheduled for more than one user. Data symbols for different users may be multiplexed according to various embodiments.

[0046] In some embodiments, a user's data symbols may be mapped to a set of contiguous DFT inputs (e.g., a set of contiguous DFT inputs may be assigned to that user). For example, in Figure 4, symbols belonging to UE1 are mapped to DFT inputs 0 to N-1, symbols belonging to UE2 are mapped to DFT inputs N to K-1, and symbols belonging to UE3 are mapped to DFT inputs K to M-1.

[0047] In some embodiments, a user may be assigned a set of non-contiguous DFT inputs. The DFT inputs may be divided into L blocks, and the inputs within each block may be contiguous. For example, block 1 may include DFT inputs {0-11}, block 2 may include DFT inputs {12-24}, and one or more of the L blocks may then be assigned to the user's data symbols. For example, in FIG. 5, the DFT inputs are divided into six blocks, bl1-bl6. The data symbols of UE1 may be mapped to blocks 1, 3, and 5, and the data symbols of UE2 may be mapped to blocks 2, 4, and 6.

[0048] In some embodiments, the receiver may need to know the resource allocation so that it can separate the UE's own data symbols at the output of the IDFT block at the receiver. The resource allocation may include the index of the DFT input to which the data symbol is mapped, the subcarrier, the index of the DFT-s-OFDM symbol with user data, the index of the slot, etc. The resource allocation, including the DFT input used for a particular user, may be transmitted and / or configured to the UE in the control information.

[0049] For contiguous mapping, the control information may include an index of the first allocated DFT input and a total number of allocated DFT inputs, as shown in FIG. 4. For distributed mapping, the control information may include a bitmap of length L (e.g., L is the number of blocks), and a bit in the bitmap may indicate whether the corresponding input block is allocated to a user. Bit 1 may indicate that the block is allocated to a user, and bit 0 may mean that the block is not allocated to a user. For example, for FIG. 5, the bitmap may include 6 bits, and the resource allocation of UE1 may be indicated by [101010], and the resource allocation of UE2 may be indicated by [010101]. At least one of the number of blocks and the number of DFT inputs per block may be set. The UE may determine the size of the DFT from the number of allocated subcarriers.

[0050] In some embodiments, the PDCCH may also be mapped to the DFT inputs. The PDCCH may include one or more control channel elements (CCEs). Each CCE may include a certain number of resources (e.g., 72 resources). Each DFT input on one DFT-s-OFDM symbol may be counted as one resource. As an example, one CCE may include 72 resources (DFT inputs) on one DFT-s-OFDM symbol. In another example, the 72 resources of a CCE may be evenly divided across three DFT-s-OFDM symbols. Figures 6 and 7 show examples of CCE to resource mapping. In these figures, as an example, each box represents 12 DFT inputs on one DFT-s-OFDM symbol. In Figure 6, the CCE includes continuous resources, and in Figure 7, the CCE includes distributed resources. In these figures, the x-axis may represent the input to the DFT in one DFT-s-OFDM symbol, and the y-axis may represent the index of the DFT-s-OFDM symbol used for the PDCCH. For example, in these figures, 36 resources of each CCE may be transmitted in one DFT-s-OFDM symbol, and the remaining 36 resources may be transmitted in a subsequent DFT-s-OFDM symbol. The number of DFT-s-OFDM symbols for transmitting all CCEs may be 1, 2, 3, or more.

[0051] The PDCCH may be mapped to one or more CCEs. In some embodiments, if the receiver does not know exactly which CCE is used to carry the PDCCH, the receiver can blind decode the PDCCH candidates. At the receiver, the resources used to form the PDCCH candidates may be after the IDFT block.

[0052] FIG. 8 illustrates a flow chart of an embodiment of a process 800 for multiplexing data of multiple users on a DFT-s-OFDM signal. The process 800 may be performed by any network node (e.g., base station 220) having transmit circuitry such as the circuitry shown in FIGS. 3-5. The process may begin at operation S802, where data associated with multiple users is received. The process proceeds to operation S804, where a DFT transform is performed on the data associated with the multiple users by a DFT precoder. The DFT precoder may correspond to any of the DFT precoders 302A, 402, and 502. The process proceeds to operation S806, where subcarrier mapping is performed on the output of the DFT precoder by a subcarrier mapper. The subcarrier mapper may map the output of the DFT precoder to a set of subcarriers. The subcarrier mapper may correspond to SM 304A. The process proceeds to operation S808, where an IDFT is performed on the output of the subcarrier mapper. The IDFT operation may be performed by IDFT 306A. The process proceeds to operation S810 where the output of the IDFT is transmitted as a DFT-s-OFDM signal over a wireless communication network.

[0053] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the implementation to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the implementations.

[0054] It is understood that the particular order or hierarchy of blocks in the processes / flowcharts disclosed herein represents an example approach. It is understood that the particular order or hierarchy of blocks within the processes / flowcharts can be rearranged based on design preferences. Also, some blocks may be combined or omitted. The accompanying method claims present various block elements in a sample order, and are not meant to be limited to the particular order or hierarchy presented.

[0055] Some embodiments may relate to systems, methods, and / or computer-readable media at any possible level of technical detail of integration. Furthermore, one or more of the above components described above may be implemented as instructions stored on a computer-readable medium and executable by at least one processor (and / or may include at least one processor). The computer-readable medium may include a computer-readable non-transitory storage medium(s) having computer-readable program instructions for causing a processor to perform operations.

[0056] A computer-readable storage medium can be a tangible device that can hold and store instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of computer-readable storage media includes portable computer diskettes, hard disks, random access memories (RAMs), read-only memories (ROMs), erasable programmable read-only memories (EPROMs or flash memories), static random access memories (SRAMs), portable compact disk read-only memories (CD-ROMs), digital versatile disks (DVDs), memory sticks, floppy disks, mechanically encoded devices such as punch cards or ridges in grooves structures with instructions recorded on them, and any suitable combination of the above. A computer-readable storage medium as used herein should not be interpreted as being itself a transitory signal such as an electric wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a wave guide or other transmission medium (e.g., a light pulse passing through a fiber optic cable), or an electrical signal transmitted through a wire.

[0057] The computer-readable program instructions described herein may be downloaded from a computer-readable storage medium into each computing / processing device, or may be downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include copper transmission cables, optical transmission fiber, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium in the respective computing / processing device.

[0058] The computer readable program code / instructions for performing the operations may be either source code or object code written in any combination of one or more programming languages, including assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, configuration data for integrated circuits, or object-oriented programming languages ​​such as Smalltalk, C++, and procedural programming languages ​​such as the "C" programming language or similar programming languages. The computer readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or wide area network (WAN), or may be externally connected (e.g., via the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuits, field programmable gate arrays (FPGAs), or programmable logic arrays (PLAs) can execute computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry to perform an aspect or operation.

[0059] These computer-readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, and the instructions executing via the processor of the computer or other programmable data processing apparatus produce means for performing the functions / operations identified in one or more blocks of the flowcharts and / or block diagrams. These computer-readable program instructions may also be stored in a computer-readable storage medium that can direct a computer, programmable data processing apparatus, and / or other device to function in a particular manner, such that a computer-readable storage medium having instructions stored therein includes an article of manufacture including instructions that implement an aspect of the function / operation identified in the block(s) of the flowcharts and / or block diagrams.

[0060] The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause the computer, other programmable apparatus, or other device to perform a series of operational steps to generate a computer-implemented process, such that the instructions executing on the computer, other programmable apparatus, or other device implement the functions / operations identified in the block(s) of the flowcharts and / or block diagrams.

[0061] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer-readable media according to various embodiments. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or part of instructions that includes one or more executable instructions for implementing a particular logical function. The methods, computer systems, and computer-readable media may include additional, fewer, different, or differently arranged blocks compared to the blocks shown in the figures. In some alternative implementations, the functions described in the blocks may be performed in a different order than the order described in the figures. For example, two blocks shown in succession may actually be executed simultaneously or substantially simultaneously, or the blocks may sometimes be executed in reverse order depending on the functionality involved. It should also be noted that each block of the block diagrams and / or flowchart diagrams, as well as combinations of blocks in the block diagrams and / or flowchart diagrams, may be implemented by a dedicated hardware-based system that executes a particular function or operation or executes a combination of dedicated hardware and computer instructions.

[0062] It will be apparent that the systems and / or methods described herein may be implemented in various forms of hardware, firmware, or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not intended to limit the implementation. Thus, the operation and behavior of the systems and / or methods are described herein without reference to specific software code, and it will be understood that software and hardware can be designed to implement the systems and / or methods based on the description herein.

[0063] The above disclosure also encompasses the embodiments listed below.

[0064] (1) A method performed by at least one processor of a network node operating in a wireless communication network, the method including: receiving data associated with a plurality of users; performing a Discrete Fourier Transform (DFT) transform on the data associated with the plurality of users by a DFT coder; performing subcarrier mapping on an output of the DFT coder by a subcarrier mapper to map an output of the DFT coder to a set of subcarriers; performing an inverse DFT (IDFT) on an output of the subcarrier mapper; and transmitting the output of the IDFT as a DFT-spread optical frequency division multiplexed (DFT-s-OFDM) signal over the wireless communication network.

[0065] (2) The method of any one of the preceding claims, wherein the DFT coder maps data associated with multiple users to multiple DFT inputs corresponding to DFT-s-OFDM blocks.

[0066] (3) The method of any one of the preceding claims, wherein the DFT coder maps data associated with the multiple users such that data for each user is mapped to a set of consecutive DFT inputs of the multiple DFT inputs.

[0067] (4) The method of any one of the preceding claims, wherein the DFT coder maps data associated with the multiple users such that data for each user is mapped to a set of non-contiguous DFT inputs of the multiple DFT inputs.

[0068] (5) The method of any one of (2) to (4), further comprising transmitting, via the wireless communication network, mapping information indicating a mapping of data of each of a plurality of users to a plurality of DFT inputs.

[0069] (6) The method of any one of features (1) to (5), further comprising mapping, by a DFT coder, one or more control channel elements (CCEs) of a physical downlink control channel (PDCCH) to a plurality of DFT inputs corresponding to the DFT-s-OFDM block.

[0070] (7) The method according to feature (6), wherein the one or more CCEs are contiguous resources.

[0071] (8) The method according to feature (6), wherein one or more CCEs are discontinuous resources.

[0072] (9) A network node operating in a wireless communication network, comprising: at least one memory configured to store computer program code; and at least one processor configured to access the at least one memory and operate as instructed by the computer program code, the computer program code including: receiving code configured to cause the at least one processor to receive data associated with a plurality of users; first execution code configured to cause the at least one processor to perform a Discrete Fourier Transform (DFT) transform on the data associated with the plurality of users with a DFT coder; second execution code configured to cause the at least one processor to perform subcarrier mapping on an output of the DFT coder with a subcarrier mapper, the subcarrier mapping mapping an output of the DFT coder to a set of subcarriers; third execution code configured to cause the at least one processor to perform an inverse DFT (IDFT) on an output of the subcarrier mapper; and transmitting code configured to cause the at least one processor to transmit the output of the IDFT as a DFT-spread optical frequency division multiplexed (DFT-s-OFDM) signal over the wireless communication network.

[0073] (10) The network node of feature (9), wherein the DFT coder maps data associated with multiple users to multiple DFT inputs corresponding to DFT-s-OFDM blocks.

[0074] (11) The network node of feature (10), wherein the DFT coder maps data associated with multiple users such that data for each user is mapped to a set of adjacent DFT inputs of the multiple DFT inputs.

[0075] (12) The network node of feature (10), wherein the DFT coder maps data associated with multiple users such that data for each user is mapped to a set of non-contiguous DFT inputs of the multiple DFT inputs.

[0076] (13) The network node of feature (10), wherein the computer program code further comprises a transmitting code configured to cause the at least one processor to transmit, over a wireless communication network, mapping information indicating a mapping of data of each user of a plurality of users to a plurality of DFT inputs.

[0077] (14) The network node of any one of features (9) to (14), wherein the computer program code further includes a mapping code configured to cause at least one processor to map, by a DFT coder, one or more control channel elements (CCEs) of a physical downlink control channel (PDCCH) to a plurality of DFT inputs corresponding to a DFT-s-OFDM block.

[0078] (15) The network node according to feature (14), wherein one or more CCEs are contiguous resources.

[0079] (16) The network node according to feature (14), wherein one or more CCEs are discontinuous resources.

[0080] (17) A non-transitory computer-readable medium having instructions stored therein that, when executed by a processor in a network node operating in a wireless communications network, cause the network node to perform a method including receiving data associated with a plurality of users; performing a discrete Fourier transform (DFT) transform on the data associated with the plurality of users by a DFT coder; performing subcarrier mapping on an output of the DFT coder by a subcarrier mapper, mapping the output of the DFT coder to a set of subcarriers; performing an inverse DFT (IDFT) on the output of the subcarrier mapper; and transmitting the output of the IDFT as a DFT-spread optical frequency division multiplexed (DFT-s-OFDM) signal over the wireless communications network.

[0081] (18) The non-transitory computer-readable medium of (17), wherein the DFT coder maps data associated with multiple users to multiple DFT inputs corresponding to DFT-s-OFDM blocks.

[0082] (19) The non-transitory computer-readable medium of feature (18), wherein the DFT coder maps data associated with multiple users such that data for each user is mapped to a set of consecutive DFT inputs of the multiple DFT inputs.

[0083] (20) The DFT coder is a DFT coder in which each user's data is a discontinuous DFT input for multiple DFT inputs. 20. The non-transitory computer-readable medium of claim 19, further comprising: a computer-readable medium for storing a plurality of user-associated data items, the plurality of user-associated data items being mapped to a set of a plurality of user-associated data items.

Claims

1. 1. A method executed by at least one processor of a network node operating in a wireless communications network, comprising: Receiving data associated with a plurality of users; performing a Discrete Fourier Transform (DFT) transform on the data associated with the plurality of users with a DFT coder; performing subcarrier mapping on the output of the DFT coder by a subcarrier mapper, the subcarrier mapping mapping the output of the DFT coder onto a set of subcarriers; performing an inverse DFT (IDFT) on the output of the subcarrier mapper; and transmitting the output of the IDFT as a Distributed Fourier Transform (DFT-s-OFDM) signal over the wireless communication network. method.

2. 2. The method of claim 1, wherein the DFT coder maps the data associated with the multiple users to multiple DFT inputs corresponding to DFT-s-OFDM blocks.

3. The method of claim 2 , wherein the DFT coder maps the data associated with the multiple users such that data for each user is mapped to a set of consecutive DFT inputs of the multiple DFT inputs.

4. The method of claim 2 , wherein the DFT coder maps the data associated with the multiple users such that each user's data is mapped to a set of non-contiguous DFT inputs of the multiple DFT inputs.

5. The method of claim 2 , further comprising: transmitting, over the wireless communication network, mapping information indicating a mapping of data of each user of the plurality of users to the plurality of DFT inputs.

6. and mapping, by the DFT coder, one or more control channel elements (CCEs) of a physical downlink control channel (PDCCH) to a plurality of DFT inputs corresponding to a DFT-s-OFDM block. The method of claim 1.

7. The method of claim 6 , wherein the one or more CCEs are contiguous resources.

8. The method of claim 6 , wherein the one or more CCEs are non-contiguous resources.

9. 1. A network node operating in a wireless communication network, comprising: at least one memory configured to store computer program code; at least one processor configured to access the at least one memory and operate as instructed by the computer program code, the computer program code comprising: receiving code configured to cause the at least one processor to receive data associated with a plurality of users; and causing the at least one processor to perform a Discrete Fourier Transform (DFT) transform on the data associated with the plurality of users by a DFT coder. a first execution code generated; second execution code configured to cause the at least one processor to perform subcarrier mapping on the output of the DFT coder by a subcarrier mapper, the output of the DFT coder being mapped to a set of subcarriers; third execution code configured to cause the at least one processor to perform an inverse DFT (IDFT) on the output of the subcarrier mapper; and a transmission code configured to cause the at least one processor to transmit the output of the IDFT as a Distributed Fourier Transform (DFT-s-OFDM) signal over the wireless communication network. Network node.

10. The network node of claim 9, wherein the DFT coder is configured to map the data associated with the multiple users to multiple DFT inputs corresponding to DFT-s-OFDM blocks.

11. The network node of claim 10 , wherein the DFT coder maps the data associated with the multiple users such that data for each user is mapped to a set of consecutive DFT inputs of the multiple DFT inputs.

12. The network node of claim 10 , wherein the DFT coder is configured to map the data associated with the multiple users such that data for each user is mapped to a set of non-contiguous DFT inputs of the multiple DFT inputs.

13. 11. The network node of claim 10, wherein the computer program code further comprises transmitting code configured to cause the at least one processor to transmit, over the wireless communication network, mapping information indicative of a mapping of data of each user of the plurality of users to the plurality of DFT inputs.

14. 10. The network node of claim 9, wherein the computer program code further comprises a mapping code configured to cause the at least one processor to map, by the DFT coder, one or more control channel elements (CCEs) of a physical downlink control channel (PDCCH) to a plurality of DFT inputs corresponding to a DFT-s-OFDM block.

15. The network node of claim 14 , wherein the one or more CCEs are contiguous resources.

16. The network node of claim 14 , wherein the one or more CCEs are non-contiguous resources.

17. A non-transitory computer readable medium having instructions stored therein, the instructions, when executed by a processor in a network node operating in a wireless communication network, causing the network node to: Receiving data associated with a plurality of users; performing, by a discrete Fourier transform (DFT) coder, a DFT transform on the data associated with the plurality of users; performing subcarrier mapping on the output of the DFT coder by a subcarrier mapper, the subcarrier mapping mapping the output of the DFT coder onto a set of subcarriers; performing an inverse DFT (IDFT) on the output of the subcarrier mapper; and transmitting the output of the IDFT as a Distributed Fourier Transform (DFT-s-OFDM) signal over the wireless communication network. Non-transitory computer-readable medium.

18. 20. The non-transitory computer-readable medium of claim 17, wherein the DFT coder maps the data associated with the multiple users to multiple DFT inputs corresponding to DFT-s-OFDM blocks.

19. 20. The non-transitory computer-readable medium of claim 18, wherein the DFT coder maps the data associated with the multiple users such that data for each user is mapped to a set of consecutive DFT inputs of the multiple DFT inputs.

20. 20. The non-transitory computer-readable medium of claim 19, wherein the DFT coder maps the data associated with the multiple users such that each user's data is mapped to a set of discontinuous DFT inputs of the multiple DFT inputs.

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