Method, apparatus, and system for signal construction in a wireless communication system

Abstract

Methods, apparatuses, and systems for signal construction in wireless communication are disclosed. In one embodiment, a method performed by a wireless communication node is disclosed. The method includes: generating a superframe based on N identical subframes, where N is an integer greater than 1; and transmitting at least one signal to a wireless communication device in the superframe.

Description

Technical Field

[0001] The present disclosure generally relates to wireless communication, and more particularly, to methods, apparatuses, and systems for signal construction in wireless communication. Background Art

[0002] With the development of the fifth-generation (5G) new radio (NR) access technology, a wide range of use cases including enhanced mobile broadband, massive machine type communication (MTC), critical MTC, etc. can be realized. To expand the utilization of the NR access technology, 5G connectivity via satellites and / or aircraft is considered a promising application. A network that includes satellites and / or aircraft to perform ground base station functions (fully or partially) is referred to as a non-terrestrial network (NTN).

[0003] In an NTN, a base station (BS) on a satellite or aircraft may move at a high speed, which results in a significant and varying Doppler effect. To mitigate the Doppler effect caused by the movement of the BS, Doppler effect pre-compensation can be performed on the BS side using the predictable trajectory of the BS. However, the coverage area of an airborne BS is generally much larger than that of a typical ground BS. In addition, the Doppler pre-compensation on the BS side can only be calculated using some given reference points in the entire coverage area, rather than based on each user equipment (UE). If the Doppler effect of the BS is notified to the UE via broadcast or unicast, the signaling overhead may increase with a shorter signaling period. Therefore, the trade-off between timely Doppler information and signaling overhead should be carefully considered.

[0004] To serve a large number of UEs within the coverage area of an airborne BS, one method is to use a downlink (DL) reference signal (RS) to estimate the frequency offset (FO) on the UE side. However, some problems have not been solved in the NTN scenario. First, the density of the DL RS in the time domain determines the range of FO estimation. Therefore, a design of the DL RS that is sufficiently dense in the time domain is required. Second, the time-frequency resources used by the DL RS determine the accuracy of FO estimation, especially in the NTN scenario with significant path loss. Therefore, the trade-off between the acceptable range / accuracy of FO estimation and the DL RS overhead should be carefully considered. Existing methods for RS-based FO estimation have a low RS density in the time domain and frequency domain, which limits the range and accuracy of FO estimation achievable on the UE side. Summary of the Invention

[0005] Exemplary embodiments disclosed herein are directed to solving problems related to one or more problems existing in the prior art, and to providing additional features that will become apparent upon reference to the following detailed description when taken in conjunction with the accompanying drawings. According to various embodiments, exemplary systems, methods, apparatuses, and computer program products are disclosed herein. However, it should be understood that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who have read this disclosure that various modifications can be made to the disclosed embodiments while remaining within the scope of this disclosure.

[0006] In one embodiment, a method performed by a wireless communication node is disclosed. The method includes: generating a superframe based on N identical subframes, where N is an integer greater than 1; and transmitting at least one signal to a wireless communication device in the superframe.

[0007] In another embodiment, a method performed by a wireless communication device is disclosed. The method includes: determining a superframe based on N identical subframes, where N is an integer greater than 1; and receiving at least one signal from a wireless communication node in the superframe.

[0008] In a different embodiment, a wireless communication node configured to perform the methods disclosed in certain embodiments is disclosed. In yet another embodiment, a wireless communication device configured to perform the methods disclosed in certain embodiments is disclosed. In another embodiment, a non-transitory computer-readable medium having computer-executable instructions stored thereon for performing the methods disclosed in certain embodiments is disclosed. The foregoing and other aspects and their implementations will be described in more detail in the drawings, the specification, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Various exemplary embodiments of the present disclosure are described in detail below with reference to the following drawings. The drawings are provided for illustrative purposes only and depict only the exemplary embodiments of the present disclosure to facilitate the reader's understanding of the present disclosure. Therefore, the drawings should not be considered as limiting the breadth, scope, or applicability of the present disclosure. It should be noted that these drawings are not necessarily drawn to scale for clarity and convenience of illustration.

[0010] Figure 1 An exemplary communication network in which the techniques disclosed herein can be implemented according to some embodiments of the present disclosure is shown.

[0011] Figure 2 A block diagram of a base station (BS) according to some embodiments of the present disclosure is shown.

[0012] Figure 3 A flowchart of a method performed by a BS according to some embodiments of the present disclosure is shown.

[0013] Figure 4 A block diagram of a user equipment (UE) according to some embodiments of the present disclosure is shown.

[0014] Figure 5 A flowchart of a method performed by a UE according to some embodiments of the present disclosure is shown.

[0015] Figure 6 An exemplary method for retransmission according to some embodiments of the present disclosure is shown.

[0016] Figure 7 A diagram of baseband signal processing with superframe generation according to some embodiments of the present disclosure is shown.

[0017] Figures 8A - 8C An exemplary method for generating a double subframe after resource mapping according to some embodiments of the present disclosure is shown.

[0018] Figures 9A - 9B An exemplary method for generating a quad subframe after resource mapping according to some embodiments of the present disclosure is shown.

[0019] Figures 10A - 10C Another exemplary method for generating a double subframe after resource mapping according to some embodiments of the present disclosure is shown.

[0020] Figure 11 A diagram of baseband signal processing using resource mapping according to the generated superframe according to some embodiments of the present disclosure is shown.

[0021] Figures 12A - 12B An exemplary method for resource mapping according to the generated double subframe according to some embodiments of the present disclosure is shown.

[0022] Figures 13A - 13B An exemplary method for resource mapping according to the generated quad subframe according to some embodiments of the present disclosure is shown. Detailed Description

[0023] The following describes various exemplary embodiments of the present disclosure with reference to the accompanying drawings to enable those of ordinary skill in the art to make and use the present disclosure. It will be apparent to those of ordinary skill in the art that various changes or modifications can be made to the examples described herein without departing from the scope of the present disclosure after reading the present disclosure. Therefore, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Additionally, the specific order and / or hierarchy of steps in the methods disclosed herein are merely exemplary methods. Based on design preferences, the specific order or hierarchy of steps of the disclosed method or process can be rearranged while remaining within the scope of the present disclosure. Therefore, those of ordinary skill in the art should understand that the methods and techniques disclosed herein present various steps or actions in a sample order, and the present disclosure is not limited to the specific order or hierarchy presented unless otherwise expressly stated.

[0024] A typical wireless communication network includes one or more base stations (commonly referred to as "BS"), each of which provides geographical radio coverage, and one or more wireless user equipment terminals (commonly referred to as "UE") that can send and receive data within the radio coverage. In a non-terrestrial network (NTN), the BS on a satellite or an aircraft can move at high speed relative to the UE associated with the BS, which results in a significant and varying Doppler effect. And repetition in signal transmission can overcome the path loss caused by long-distance propagation and large coverage in NTN. The present teachings propose a novel method that utilizes the advantage of repeated transmission to achieve high-range and high-precision frequency offset estimation (FOE) without additional requirements for reference signals (RS).

[0025] In some embodiments of the present teachings, to cope with the Doppler effect caused by the movement of the BS in the NTN scenario, repeated transmission can be used to enable data-assisted FOE. For example, the same orthogonal frequency division multiplexing (OFDM) symbols form a symbol group to facilitate FOE before channel estimation (CE) and equalization (EQU). The disclosed method can at least: (1) significantly improve the accuracy of FOE without additional requirements for RS resources, (2) significantly increase the range of FOE to cope with larger Doppler, and (3) effectively reduce the receiver complexity by using FOE before CE and EQU.

[0026] The methods disclosed in this teaching can be implemented in a wireless communication network, where the BS and the UE can communicate with each other via a communication link (e.g., via a downlink radio frame from the BS to the UE or via an uplink radio frame from the UE to the BS). In various embodiments, the BS in this disclosure can be referred to as the network side and can include or be implemented as a next-generation node B (gNB), an E-UTRAN node B (eNB), a transmit / receive point (TRP), an access point (AP), a non-terrestrial receiving point for satellite / hot air balloon / unmanned aerial vehicle (UAV) communication, a radio transceiver in a vehicle of a vehicle-to-vehicle (V2V) wireless network, etc.; while the UE in this disclosure can be referred to as a terminal and can include or be implemented as a mobile station (MS), a station (STA), a ground device for satellite / hot air balloon / UAV communication, a radio transceiver in a vehicle of a vehicle-to-vehicle (V2V) wireless network, and so on. According to various embodiments of this disclosure, the BS and the UE can be described herein as non-limiting examples of "wireless communication nodes" and "wireless communication devices" respectively, which can implement the methods disclosed herein and can be capable of wireless and / or wired communication.

[0027] Exemplary communication network 100 in which the techniques disclosed herein can be implemented, according to some embodiments of this disclosure. As Figure 1 shown, the exemplary communication network 100 is an NTN scenario, which includes a base station (BS) 101 on a satellite and multiple UEs 110, 120, where the BS 101 can communicate with the UEs according to a wireless protocol. In this example, the satellite moves at a speed Vsat while transmitting a beam to the UEs.

[0028] To cope with the Doppler effect caused by the movement of the BS, as Figure 1 shown, Doppler pre-compensation can be performed on the BS side. The Doppler effect caused by the predictable movement of the BS is pre-compensated for each beam, which results in a zero downlink Doppler frequency offset experienced at the beam center or some other given reference point. However, the residual Doppler in the beam may still be large at positions other than the beam center or some other given reference point.

[0029] To facilitate the estimation of the Doppler caused by the movement of the BS in the NTN scenario, DL RS can be used. The DL RS design in a typical communication system has a low RS density, which limits the range and accuracy of the FOE achievable on the UE side.

[0030] In one example, in the Long-Term Evolution (LTE) cell-specific reference signal (CRS) resource mapping for two antenna ports, for the LTE-CRS on each antenna port, only 2 resource elements (REs) spaced 7 OFDM symbols apart are used every 1 millisecond (ms). Similarly, for the LTE CRS on each antenna port, only 2 REs are used per physical resource block (PRB). Therefore, the range and accuracy of the FOE using the LTE CRS are limited.

[0031] In another example, in the narrowband Internet of Things (NB-IoT) RS resource mapping for two antenna ports, on each antenna port, only 2 REs spaced 7 OFDM symbols apart are used every 1 ms, and on each antenna port, only 2 REs are used per PRB. Therefore, the range and accuracy of the FOE using the NB-IoT RS are also limited.

[0032] In yet another example, in the NR demodulation reference signal (DMRS) resource mapping for four antenna ports (each antenna port corresponding to a given UE), on each antenna port, only 2 REs spaced 0 OFDM symbols apart every 1 ms are used; and on each antenna port, after orthogonal cover code (OCC) merging, only 3 REs are used per PRB. Therefore, the range and accuracy of the FOE using the NR DMR are also limited.

[0033] In various embodiments of the present teachings, repeated transmissions can be used to enable data-aided FOE, where multiple identical OFDM symbols can form a symbol group in a super subframe to facilitate FOE. In one embodiment, N (N > 1 and N ≤ repetition time) identical subframes in the repetition are used to construct the super subframe. For example, the super subframe can be a double subframe with N = 2, or a quaternary-subframe or quadruple-subframe with N = 4. In the super subframe, the symbol group is composed of N identical symbols. The identical symbols are bit-level identical. That is, they have the same bits after bit-level scrambling. The symbol-level scrambling may be different.

[0034] In various embodiments of the present teachings, the super subframe is a signal structure having consecutive identical symbols in the time domain after repetition. The super subframe can also be regarded as a repetition pattern generated by a designed resource mapping or super subframe generation method.

[0035] In one embodiment, the super subframe can be constructed by a symbol group built after resource mapping. In another embodiment, the super subframe can be constructed in the resource mapping through symbol-level repetition.

[0036] To generate superframes, the network may notify the UE of the value of N (the number of subframes in a superframe), which can be carried by broadcast signaling or UE-specific signaling. In time-frequency domain resource mapping, symbol-level interleaving (column swapping) or puncturing techniques can be utilized to enable coexistence of data signals and reference signals.

[0037] In one embodiment, the repetition period of the superframe can be used throughout the repetition to improve timely reception response. The value of L (the number of identical subframes in the superframe repetition period) can be notified by the network to the UE, which can be carried by broadcast or UE-specific signaling.

[0038] To ensure that the same symbol bits form the same symbol group, re-initialization of the bit-level scrambling sequence can be performed at the start of each superframe. Re-initialization of the bit-level scrambling sequence can also be performed at the start of the superframe repetition period, as long as the symbol bits in the symbol group are the same.

[0039] Figure 2 A block diagram of a base station (BS) 200 according to some embodiments of the present disclosure is shown. BS 200 is an example of a device that can be configured to implement the various methods described herein. As Figure 2 shown, BS 200 includes a housing 240 that contains a system clock 202, a processor 204, a memory 206, a transceiver 210 including a transmitter 212 and a receiver 214, a power module 208, a superframe generator 220, a repetition period determiner 222, a subframe number determiner 224, and a data and reference signal generator 226.

[0040] In this embodiment, the system clock 202 provides a timing signal to the processor 204 for controlling the timing of all operations of BS200. The processor 204 controls the general operation of BS 200 and may include one or more processing circuits or modules such as any combination of a central processing unit (CPU) and / or a general-purpose microprocessor, a microcontroller, a digital signal processor (DSP), a field-programmable gate array (FPGA), a programmable logic device (PLD), a controller, a state machine, gated logic, discrete hardware components, a dedicated hardware finite state machine, or any other suitable circuit, device, and / or structure capable of performing calculations or other operations on data.

[0041] A memory 206 that can include a read-only memory (ROM) and a random access memory (RAM) can provide instructions and data to a processor 204. A portion of the memory 206 can also include a non-volatile random access memory (NVRAM). The processor 204 generally performs logical and arithmetic operations based on program instructions stored within the memory 206. The instructions (also referred to as software) stored in the memory 206 can be executed by the processor 204 to perform the methods described herein. The processor 204 and the memory 206 together form a processing system that stores and executes software. As used herein, "software" refers to any type of instructions, whether referring to software, firmware, middleware, microcode, etc., that can configure a machine or device to perform one or more desired functions or processes. The instructions can include code (e.g., in source code format, binary code format, executable code format, or any other suitable code format). When executed by one or more processors, these instructions cause the processing system to perform the various functions described herein.

[0042] A transceiver 210 that includes a transmitter 212 and a receiver 214 allows the BS 200 to send data to and receive data from a remote device (e.g., a UE or another BS). An antenna 250 is typically attached to the housing 240 and electrically coupled to the transceiver 210. In various embodiments, the BS 200 includes (not shown) multiple transmitters, multiple receivers, and multiple transceivers. In one embodiment, the antenna 250 is replaced by a multi-antenna array 250 that can form multiple beams, each beam pointing in a different direction. The transmitter 212 can be configured to wirelessly send data packets having different data packet types or functions, such data packets being generated by the processor 204. Similarly, the receiver 214 is configured to receive data packets having different data packet types or functions, and the processor 204 is configured to process data packets of a variety of different data packet types. For example, the processor 204 can be configured to determine the type of a data packet and accordingly process the data packet and / or fields of the data packet.

[0043] In wireless communication with a frequency offset (e.g., due to relative movement between the BS 200 and the UE), a superframe generator 220 can generate a superframe based on N identical subframes, where N is an integer that is a positive power of 2 (e.g., 2, 4, 8, 16, etc.). In this example, a subframe number determiner 224 can determine and notify the UE about the value of N via broadcast signaling or specific signaling. In this example, a data and reference signal generator 226 can generate at least one signal in the superframe and transmit it via the transmitter 212 to the UE for frequency offset estimation at the UE. The at least one signal can include a data signal and / or a reference signal. According to various embodiments, the superframe is generated after or during time-frequency domain resource mapping.

[0044] In one embodiment, each of the N identical subframes is obtained from a codeword that is to be repeated M times. In one example, M is an integer that is a positive power of 2 (e.g., 2, 4, 8, 16, etc.). In one embodiment, the codeword occupies N_SF subframes before repetition; and after repetition with a repetition period of N_SF*min(M, 4), it occupies N_SF*M subframes, where min(M, 4) represents the minimum of M and 4, N_SF is an integer between 1 and 10, and N is less than or equal to M.

[0045] In another embodiment, after repetition with a repetition period of N_SF*L, the codeword occupies N_SF*M superframes, where L is an integer between 2 and M, and N_SF is an integer between 1 and 10. In this case, the repetition period determiner 222 can determine and notify the UE about the value of L via broadcast signaling or specific signaling.

[0046] In one embodiment, each of the N identical subframes includes a plurality of symbols. A superframe includes a plurality of symbol groups, and each in the symbol groups respectively includes N identical symbols from the N identical subframes. Further, after bit-level scrambling based on a bit-level scrambling sequence, the N identical symbols are bit-level identical.

[0047] In one embodiment, the superframe generator 220 can generate a plurality of superframes including superframes based on a codeword repeated M times. The N identical symbols after repetition are continuous in the time domain. Re-initialization of the bit-level scrambling sequence is performed at the start of each superframe.

[0048] In another embodiment, the superframe generator 220 can generate a plurality of superframes including superframes based on a codeword repeated M times. Re-initialization of the bit-level scrambling sequence is performed at the start of every K superframes, where K is a positive integer.

[0049] In one embodiment, in the time-frequency domain resource mapping for transmitting a data signal in a superframe, a plurality of symbol groups are mapped to the superframe, and puncturing is performed on the resource elements of the data signal to also transmit a reference signal in the superframe. In this case, after the time-frequency domain resource mapping, the N identical symbols in each of the plurality of symbol groups are continuous in the time domain.

[0050] In another embodiment, in the time-frequency domain resource mapping for transmitting a data signal in a superframe, a plurality of symbol groups are mapped to the superframe, and symbol-level interleaving is also used to allocate resource elements for transmitting a reference signal in the superframe. In this case, after the time-frequency domain resource mapping, at least two of the N identical symbols in at least one of the plurality of symbol groups are not continuous in the time domain.

[0051] The power supply module 208 may include a power supply such as one or more batteries and a power regulator to supply regulated power to each of the above modules in Figure 2 . In some embodiments, if the BS 200 is coupled to a dedicated external power supply (e.g., a wall power outlet), the power supply module 208 may include a transformer and a power regulator.

[0052] The various modules discussed above are coupled together by a bus system 230. The bus system 230 may include a data bus, and in addition to the data bus, for example, a power bus, a control signal bus, and / or a status signal bus. It should be understood that the modules of the BS 200 may be operatively coupled to each other using any suitable technology and medium.

[0053] Although Figure 2 shows many separate modules or components, those of ordinary skill in the art should understand that one or more modules may be combined or co-implemented. For example, the processor 204 may not only implement the functions described above with respect to the processor 204, but also implement the functions described above with respect to the super subframe generator 220. Conversely, Figure 2 each module shown in

[0054] Figure 3 shows a flowchart of a method 300 performed by a BS (e.g., the BS 200 in Figure 2 ) according to some embodiments of the present disclosure. At operation 302, the BS generates a super subframe based on N identical subframes from a codeword. At operation 304, the BS sends the value of N to the UE, where the value of N is the number of identical subframes used to generate the super subframe. Optionally, at operation 306, the BS sends the value of L related to the repetition period of the codeword to the UE. At operation 308, the BS sends at least one repeated signal to the UE in the super subframe, for example, for frequency offset estimation. Figure 3 The order of operations shown in

[0055] Figure 4 shows a block diagram of a UE 400 according to some embodiments of the present disclosure. The UE 400 is an example of a device that may be configured to implement the various methods described herein. As Figure 4 shown, the UE 400 includes a housing 440 that contains a system clock 402, a processor 404, a memory 406, a transceiver 410 including a transmitter 412 and a receiver 414, a power supply module 408, a super subframe determiner 420, a signal analyzer 422, a frequency offset estimator 424, and a super subframe parameter analyzer 426.

[0056] In this embodiment, the system clock 402, the processor 404, the memory 406, the transceiver 410, and the power supply module 408 operate in a manner similar to the system clock 202, the processor 204, the memory 206, the transceiver 210, and the power supply module 208 in BS 200. The antenna 450 or the multi-antenna array 450 is generally attached to the housing 440 and electrically coupled to the transceiver 410.

[0057] In this example, the superframe determiner 420 may determine a superframe based on N identical subframes, where N is an integer equal to a positive power of 2 (e.g., 2, 4, 8, 16, etc.). The superframe parameter analyzer 426 in this example may receive the value of N from the BS via the receiver 414 through broadcast signaling or specific signaling. The signal analyzer 422 in this example may receive and analyze at least one signal in the superframe via the receiver 414. The at least one signal may include a data signal and / or a reference signal. According to various embodiments, the superframe is generated after or during the time-frequency domain resource mapping. The frequency offset estimator 424 in this example may perform frequency offset estimation at least partially based on the superframe.

[0058] In one embodiment, each of the N identical subframes is obtained from a codeword to be repeated M times. In one example, M is an integer equal to a positive power of 2 (e.g., 2, 4, 8, 16, etc.). In one embodiment, the codeword occupies N_SF subframes before repetition; and after repetition with a repetition period of N_SF*min(M, 4), it occupies N_SF*M subframes, where min(M, 4) represents the minimum of M and 4, N_SF is an integer between 1 and 10, and N is less than or equal to M.

[0059] In another embodiment, after repetition with a repetition period of N_SF*L, the codeword occupies N_SF*M superframes, where L is an integer between 2 and M, and N_SF is an integer between 1 and 10. In this case, the superframe parameter analyzer 426 may receive the value of L from the BS via the receiver 414 through broadcast signaling or specific signaling.

[0060] In one embodiment, each of the N identical subframes includes multiple symbols. The superframe includes multiple symbol groups, and each in the symbol group includes N identical symbols from the N identical subframes respectively. In addition, after bit-level scrambling based on a bit-level scrambling sequence, the N identical symbols are bit-level identical.

[0061] In one embodiment, the superframe determiner 420 may determine multiple superframes including a superframe based on a codeword repeated M times. The N identical symbols after repetition are continuous in the time domain. Re-initialization of the bit-level scrambling sequence is performed at the start of each superframe.

[0062] In another embodiment, the super subframe determiner 420 may determine a plurality of super subframes including super subframes based on a codeword repeated M times. Re-initialization of the bit-level scrambling sequence is performed at the start of every K super subframes, where K is a positive integer.

[0063] In one embodiment, in the time-frequency domain resource mapping for transmitting a data signal in a super subframe, a plurality of symbol groups are mapped to the super subframe, and puncturing is performed on the resource elements of the data signal to also transmit a reference signal in the super subframe. In this case, after the time-frequency domain resource mapping, N identical symbols in each of the plurality of symbol groups are consecutive in the time domain.

[0064] In another embodiment, in the time-frequency domain resource mapping for transmitting a data signal in a super subframe, a plurality of symbol groups are mapped to the super subframe, and resource elements for transmitting a reference signal in the super subframe are also allocated using symbol-level interleaving. In this case, after the time-frequency domain resource mapping, at least two of the N identical symbols in at least one of the plurality of symbol groups are non-consecutive in the time domain.

[0065] In some embodiments, the UE may send the generated super subframe to the BS such that the BS can perform frequency offset estimation on the BS side. That is, frequency offset estimation may be performed based on uplink transmission or downlink transmission.

[0066] The various modules discussed above are coupled together by a bus system 430. The bus system 430 may include a data bus, and in addition to the data bus, for example, a power bus, a control signal bus, and / or a status signal bus. It should be understood that the modules of the UE 400 may be operatively coupled to each other using any suitable technology and medium.

[0067] Although Figure 4 shows many separate modules or components, those of ordinary skill in the art should understand that one or more modules may be combined or co-implemented. For example, the processor 404 may not only implement the functions described above regarding the processor 404, but also implement the functions described above regarding the super subframe determiner 420. Conversely, Figure 4 each module shown in

[0068] Figure 5 shows, according to some embodiments of the present disclosure, by a UE (e.g., Figure 4Flowchart of method 500 executed by UE 400 in []. At operation 502, the UE receives the value of N from the BS via broadcast or specific signaling. At operation 504, the UE determines the structure of the superframe constructed based on N identical subframes from the codeword. Optionally, at operation 506, the UE receives the value of L related to the repetition period of the codeword from the BS. At operation 508, the UE receives at least one repeated signal from the BS in the superframe. At operation 510, the UE performs frequency offset estimation at least partially based on the superframe. Figure 5 The order of operations shown in [] may be changed according to different embodiments of the present disclosure.

[0069] Different embodiments of the present disclosure will be described in detail below. It should be noted that the features of the embodiments and examples in the present disclosure can be combined with each other in any way without conflict.

[0070] Figure 6 An exemplary method for repeated transmission according to some embodiments of the present disclosure is shown. As Figure 6 shown, repeated transmission can be used to combat large path loss. For example, in NB-IoT, repeatability in both UL and DL is used to achieve sufficient combining gain. Taking the narrowband physical downlink shared channel (NPDSCH) as an example, a codeword occupying N SF subframes is repeated times. The time-domain resource mapping is as Figure 6 shown. N SF subframes are repeated times. If then it is followed by another repetition period of length until subframes are transmitted.

[0071] In the first embodiment, Figure 7 a baseband signal processing diagram 700 is shown. A superframe generation block is added at operation 770. To generate a superframe, the network should notify the UE of the value of N (the number of subframes in the superframe), which can be carried by broadcast or specific signaling of the UE.

[0072] In the first example, before modulation 720, bit-level scrambling 710 is usually performed. To enable data-assisted FOE, multiple OFDM symbols with the same bit-level scrambling can be grouped according to their repetition pattern. Taking NB-IoT-PDSCH without carrying the broadcast control channel (BCCH) as an example, the resource mapping is designed as Figures 8A to 8C shown.

[0073] In Figure 8A at operations 1 and 2, the codeword occupies using the repetition period of sub - frames, where N SF ∈ [1, 2, 3, 4, 5, 6, 8, 10] and

[0074] If then 2 adjacent sub - frames can be used at operation 3 in Figure 8A to construct a double sub - frame. The symbol 0s in 2 identical adjacent sub - frames are grouped and mapped to the first two symbols in the double sub - frame; the symbol 1s in 2 identical adjacent sub - frames are grouped and mapped to the next two symbols in the double sub - frame; and so on, such that all 14 symbol groups form the double sub - frame. A series of double sub - frames are formed in the same way. The double sub - frame construction can be specified by using the resource mapping rule or symbol - level interleaving rule between sub - frames.

[0075] In the stand - alone deployment, the narrow - band reference signal (NRS) on 2 antenna ports R0, R1 occupies the REs highlighted in Figure 8B and Figure 8C There are 2 options for OFDM symbol mapping, as shown in Figure 8B and Figure 8C respectively. The OFDM symbol index (k, l) is marked, where k and l represent the time - domain index and frequency - domain index respectively.

[0076] As shown in operation 4 - 1 in Figure 8B symbol - level interleaving or column swapping can be used to reserve REs for the NRS on antenna ports R0 and R1, where the swapped symbol indices are marked.

[0077] As shown in operation 4 - 2 in Figure 8C puncturing can be used to allocate REs for the NRS on antenna ports R0 and R1. The REs occupied by the NRS cannot be used for NPDSCH mapping, and the corresponding OFDM symbols are punctured.

[0078] In the second example, a method similar to that in the first example can be used to enable data - assisted FOE, where the resource mapping is designed as shown in Figures 9A to 9B At operations 1 and 2 in Figure 9A the codeword uses the repetition period of to occupy sub - frames, where N SF ∈ [1, 2, 3, 4, 5, 6, 8, 10] and

[0079] When then, as shown in Figure 9AAs shown in operation 3 in [reference], four adjacent subframes can be used to construct a quaternary subframe. The symbol 0 in four identical adjacent subframes is grouped and mapped to the first four symbols in the quaternary subframe; the symbol 1 in four identical adjacent subframes is grouped and mapped to the next four symbols in the quaternary subframe; and so on. In total, 14 symbol groups form a quaternary subframe. A series of quaternary subframes are formed in the same way. The quaternary subframe construction can be specified by using the resource mapping rule or the symbol-level interleaving rule between subframes.

[0080] In the stand-alone deployment, the NRS on two antenna ports R0 and R1 occupies the Figure 9B highlighted REs in [reference]. The REs occupied by the NRS cannot be used for NPDSCH mapping, and the corresponding OFDM symbols are punctured. The OFDM symbol index (k, l) is marked, where k and l represent the time-domain index and the frequency-domain index, respectively.

[0081] In the third example, as Figure 10A shown, different repetition patterns can be used in the transmission, in which the codeword occupies SF subframes with a repetition period of N subframes.

[0082] If then at operation 3 in [reference], two identical subframes from adjacent repetition periods can be used to construct a dual subframe. To ensure that the two subframes are bit-level identical, the re-initialization of bit-level scrambling can be performed at the start of every other repetition period as Figure 10A shown. Figure 10A shown.

[0083] The symbol 0 in two identical adjacent subframes is grouped and mapped to the first two symbols in the dual subframe; the symbol 1 in two identical adjacent subframes is grouped and mapped to the next two symbols in the dual subframe; and so on. In total, 14 symbol groups form the dual subframe. A series of dual subframes are formed in the same way. The dual subframe construction can be specified by using the resource mapping rule or the symbol-level interleaving rule between subframes.

[0084] In the stand-alone deployment, the NRS on two antenna ports occupies the highlighted REs as Figure 10B and Figure 10C shown. There are two options for OFDM symbol mapping, as Figure 10B and Figure 10C shown, respectively. The OFDM symbol index (k, l) is marked, where k and l represent the time-domain index and the frequency-domain index, respectively.

[0085] As Figure 10BAs shown in operation 4-1 in [reference], symbol-level interleaving or column swapping can be used to reserve REs for NRS on antenna ports R0 and R1, where the swapped symbol indices are marked.

[0086] As Figure 10C shown in operation 4-2 in [reference], puncturing can be used to allocate REs for NRS on antenna ports R0 and R1. The REs occupied by NRS cannot be used for NPDSCH mapping, and the corresponding OFDM symbols are thus punctured.

[0087] In the second embodiment, Figure 11 the baseband signal processing diagram 1100 is shown in [reference]. A superframe can be generated in the resource mapping block 1140, where symbol-level repetition is performed. To generate a superframe, the value of N (the number of subframes in the superframe) can be notified to the UE by the network, and this value can be carried via broadcast or UE-specific signaling.

[0088] In the fourth example according to the second embodiment, bit-level scrambling 1110 is typically performed before modulation 1120. To enable data-assisted FOE, multiple OFDM symbols with the same bit-level scrambling can be mapped using symbol-level repetition. In Figure 12A operation 1 in [reference], the codeword includes N SF subframes and will be repeated times.

[0089] If then a double subframe with symbol-level repetition in the resource mapping can be constructed at operation 2 in Figure 12A [reference]. The symbol 0 in two identical adjacent subframes is grouped and mapped to the first two symbols in the double subframe; the symbol 1 in two identical adjacent subframes is grouped and mapped to the next two symbols in the double subframe; and so on. A total of 14 symbol groups form the double subframe. A series of double subframes are formed in the same way. The double subframe construction can be specified using resource mapping rules or symbol-level interleaving rules between subframes.

[0090] In the stand-alone deployment, the NRS on two antenna ports R0 and R1 occupies the REs highlighted in Figure 12A [reference]. There are two options for OFDM symbol mapping, as shown in operations 3-1 and 3-2 respectively. The OFDM symbol index (k, l) is marked, where k and l represent the time-domain index and the frequency-domain index respectively.

[0091] As Figure 12A shown in operation 3-1 in [reference], symbol-level interleaving or column swapping can be used to reserve REs for NRS on antenna ports R0 and R1, where the swapped symbol indices are marked.

[0092] AsFigure 12A As shown in operation 3-2 in [reference], punching can be used to allocate REs for NRS on antenna ports R0 and R1. The REs occupied by NRS cannot be used for NPDSCH mapping, and the corresponding OFDM symbols are thus punched.

[0093] To complete a subframe, there are two options at operations 4-1 and 4-2 as shown in Figure 12B [reference]. As shown in operation 4-1 in Figure 12B [reference], where each of twin subframes 1 to twin subframe NSF is repeated times to continuously occupy twin subframes; and twin subframes 1 to N SF are concatenated in the time domain. As shown in operation 4-2 in Figure 12B [reference], where a repetition period of L·N SF (where ) subframes (twin subframes) is constructed and then concatenated. The latter structure can enable more timely reception processing at the UE side with less energy consumption. That is, the UE can stop its reception immediately after it successfully decodes the codeword using the received repetition period.

[0094] In the fifth example according to the second embodiment, a method similar to that in the fourth example can be used to enable data-assisted FOE, where multiple OFDM symbols with the same bit-level scrambling can be mapped using symbol-level repetition. At Figure 13A operation 1 in [reference], the codeword includes N SF subframes and will be repeated times.

[0095] When , resource mapping with symbol-level repetition can be used at Figure 13A operation 2 in [reference] to construct a quaternary subframe. Symbols 0 in 4 identical adjacent subframes are grouped and mapped to the first four symbols in the quaternary subframe; symbols 1 in 4 identical adjacent subframes are grouped and mapped to the next four symbols in the quaternary subframe; and so on. In total, 14 symbol groups form a quaternary subframe. A series of quaternary subframes are formed in the same way. The quaternary subframe construction can be specified by resource mapping rules or symbol-level interleaving rules between subframes.

[0096] In the stand-alone deployment, the NRS on two antenna ports R0 and R1 occupies the REs highlighted at Figure 13A operation 3 in [reference]. The REs occupied by NRS cannot be used for NPDSCH mapping, and the corresponding OFDM symbols are punched. The OFDM symbol index (k, l) is marked, where k and l represent the time-domain index and frequency-domain index respectively.

[0097] To complete sub - frames, there are two options. One is as shown in Figure 13B 4 - 1, where sub - frames (in this example, which refers to quaternary sub - frames) 1 to sub - frame N SF are each repeated times to continuously occupy sub - frames; and sub - frames 1 to N SF are connected in the time domain. The other is as shown in Figure 13B 4 - 2, where the repetition period of L·N SF (where ) sub - frames (quaternary sub - frames) is constructed and then connected. The latter structure can enable more timely reception processing at the UE side with less energy consumption. That is, the UE can stop its reception immediately after it successfully decodes the codeword using the received repetition period.

[0098] In this application, the technical features in various embodiments and examples can be combined and used in one embodiment without conflict. Each embodiment is merely an exemplary embodiment of this application.

[0099] Although the various embodiments of the present disclosure have been described above, it should be understood that they are presented only by way of example and not by way of limitation. Similarly, the various figures may depict example architectures or configurations, which are provided to enable those of ordinary skill in the art to understand the exemplary features and functions of the present disclosure. However, these persons should understand that the present disclosure is not limited to the shown example architectures or configurations, but can be implemented using a variety of alternative architectures and configurations. Additionally, as should be understood by those of ordinary skill in the art, one or more features of one embodiment can be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of the present disclosure should not be limited by any of the exemplary embodiments described above.

[0100] It should also be understood that any reference to elements using names such as "first", "second", etc. generally does not limit the number or order of these elements. Instead, these names are used herein as a convenient means to distinguish two or more elements or element instances. Thus, the reference to a first element and a second element does not mean that only two elements can be employed, or that the first element must be located before the second element in some manner.

[0101] In addition, those of ordinary skill in the art should understand that any of a variety of different technologies and processes can be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, and symbols, as may be referred to in the above description, can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0102] Those of ordinary skill in the art should also understand that any of the various illustrative logical blocks, modules, processors, means, circuits, methods, and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., digital implementations, analog implementations, or a combination of both), firmware, various forms of programs or design code incorporating instructions (which for convenience may be referred to herein as “software” or “software modules”), or any combination of these technologies.

[0103] To clearly illustrate this interchangeability of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software, or as a combination of these technologies, depends upon the particular application and design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in various ways for each particular application, but such implementation decisions do not result in a departure from the scope of the present disclosure. According to various embodiments, a processor, device, component, circuit, structure, machine, module, etc. can be configured to perform one or more of the functions described herein. As used herein, the terms “configured to” or “configured for” with respect to a particular operation or function refer to a processor, device, component, circuit, structure, machine, module, etc. that is physically constructed, programmed, and / or arranged to perform the specified operation or function.

[0104] Furthermore, those of ordinary skill in the art should understand that the various illustrative logical blocks, modules, devices, components, and circuits described herein can be implemented within or performed by an integrated circuit (IC) that includes a general - purpose processor, a digital signal processor (DSP), an application - specific integrated circuit (ASIC), a field - programmable gate array (FPGA), or other programmable logic device, or any combination thereof. The logical blocks, modules, and circuits can further include an antenna and / or a transceiver to communicate with various components within a network or within a device. The general - purpose processor can be a microprocessor, but in an alternative, the processor can be any conventional processor, controller, or state machine. The processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration for performing the functions described herein.

[0105] If implemented in software, the functions can be stored as one or more instructions or code on a computer-readable medium. Accordingly, the steps of the methods or algorithms disclosed herein can be implemented as software stored on a computer-readable medium. Computer-readable media include computer storage media and communication media, and communication media includes any medium that enables a computer program or code to be transferred from one place to another. Storage media can be any available medium accessible by a computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and that is accessible by a computer.

[0106] In this document, the term "module" as used herein refers to software, firmware, hardware, and any combination of these elements for performing the related functions described herein. Additionally, for purposes of discussion, the various modules are described as discrete modules; however, it will be apparent to one of ordinary skill in the art that two or more modules can be combined to form a single module that performs the associated functions in accordance with embodiments of the present disclosure.

[0107] Additionally, a memory or other memory and communication components can be employed in embodiments of the present disclosure. It should be understood that, for clarity, the above description has described embodiments of the present disclosure with reference to different functional units and processors. However, it will be apparent that any suitable functional distribution between different functional units, processing logic elements, or domains can be used without departing from the present disclosure. For example, functions shown to be performed by separate processing logic elements or controllers can be performed by the same processing logic element or controller. Accordingly, the reference to a particular functional unit is only a reference to a suitable means for providing the described functionality and is not an indication of a strict logical or physical structure or organization.

[0108] Various modifications to the embodiments described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the scope of the disclosure. Therefore, the disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as set forth in the following claims.

Claims

1. A method performed by a wireless communication node, the method comprising: generating a superframe based on N identical subframes, wherein each of the N identical subframes includes a plurality of symbols, the superframe includes a plurality of symbol groups, and each symbol group of the plurality of symbol groups respectively includes N identical symbols from the N identical subframes, wherein, after bit-level scrambling based on a bit-level scrambling sequence, the N identical symbols are bit-level identical, and wherein N is an integer greater than 1; and transmitting at least one signal to a wireless communication device in the superframe.

2. The method according to claim 1, wherein: each of the N identical subframes is obtained from a codeword to be repeated M times; and M is an integer greater than 1.

3. The method according to claim 2, wherein: N is an integer equal to a positive power of 2; M is an integer equal to a positive power of 2; and N is less than or equal to M.

4. The method according to claim 2, wherein: after repeating with a repetition period of N_SF*L, the codeword occupies N_SF*M subframes; L is an integer between 2 and M; and N_SF is a positive integer.

5. The method according to claim 4, further comprising: notifying the wireless communication device of the value of L through broadcast signaling or specific signaling.

6. The method according to claim 1, further comprising: generating a plurality of superframes including the superframe based on a codeword repeated M times, wherein: the N identical symbols after repetition are continuous in the time domain; and re-initialization of the bit-level scrambling sequence is performed at the start of each superframe.

7. The method according to claim 1, further comprising: generating a plurality of superframes including the superframe based on a codeword repeated M times, wherein: re-initialization of the bit-level scrambling sequence is performed at the start of every K superframes; and K is a positive integer.

8. The method according to claim 1, wherein: in a time-frequency domain resource mapping for transmitting a data signal in the superframe, the plurality of symbol groups are mapped to the superframe, and puncturing is performed on resource elements corresponding to the data signal to also transmit a reference signal in the superframe; and after the time-frequency domain resource mapping, the N identical symbols in each symbol group of the plurality of symbol groups are continuous in the time domain.

9. The method according to claim 1, wherein: in a time-frequency domain resource mapping for transmitting a data signal in the superframe, the plurality of symbol groups are mapped to the superframe, and symbol-level interleaving is further used to allocate resource elements for transmitting a reference signal in the superframe; and after the time-frequency domain resource mapping, at least two of the N identical symbols in at least one symbol group of the plurality of symbol groups are not continuous in the time domain.

10. The method according to claim 1, wherein: the superframe is generated after or during the time-frequency domain resource mapping.

11. The method according to claim 1, further comprising: Notify the wireless communication device about the value of N via broadcast signaling or specific signaling.

12. A method performed by a wireless communication device, the method comprising: Determining a superframe based on N identical subframes, wherein each of the N identical subframes includes a plurality of symbols, the superframe includes a plurality of symbol groups, and each symbol group in the plurality of symbol groups respectively includes N identical symbols from the N identical subframes, wherein, after bit-level scrambling based on a bit-level scrambling sequence, the N identical symbols are bit-level identical, and wherein N is an integer greater than 1; and Receiving at least one signal from a wireless communication node in the superframe.

13. The method according to claim 12, wherein: Each of the N identical subframes is obtained from a codeword to be repeated M times; and M is an integer greater than 1.

14. The method according to claim 13, wherein: N is an integer equal to a positive power of 2; M is an integer equal to a positive power of 2; and N is less than or equal to M.

15. The method according to claim 13, wherein: After repeating with a repetition period of N_SF*L, the codeword occupies N_SF*M subframes; L is an integer between 2 and M; and N_SF is a positive integer.

16. The method according to claim 15, further comprising: Receiving the value of L from the wireless communication node via broadcast signaling or specific signaling.

17. The method according to claim 12, further comprising: Determining a plurality of superframes including the superframe based on a codeword repeated M times, wherein: The N identical symbols after repetition are consecutive in the time domain; and Re-initialization of the bit-level scrambling sequence is performed at the start of each superframe.

18. The method according to claim 12, further comprising: Determining a plurality of superframes including the superframe based on a codeword repeated M times, wherein: Re-initialization of the bit-level scrambling sequence is performed at the start of every K superframes; and K is a positive integer.

19. The method according to claim 12, wherein: In a time-frequency domain resource mapping for receiving a data signal in the superframe, the plurality of symbol groups are mapped to the superframe, and puncturing is performed on resource elements corresponding to the data signal to also receive a reference signal in the superframe; And After the time-frequency domain resource mapping, the N identical symbols in each symbol group of the plurality of symbol groups are consecutive in the time domain.

20. The method according to claim 12, wherein: In a time-frequency domain resource mapping for receiving a data signal in the superframe, the plurality of symbol groups are mapped to the superframe, and symbol-level interleaving is also used to allocate resource elements for receiving a reference signal in the superframe; And After the time-frequency domain resource mapping, at least two of the N identical symbols in at least one symbol group of the plurality of symbol groups are non-consecutive in the time domain.

21. The method according to claim 12, wherein: The superframe is determined after or during the time-frequency domain resource mapping.

22. The method according to claim 12, further comprising: receiving the value of N from the wireless communication node via a broadcast signaling or a specific signaling.

23. A wireless communication node, comprising a processor and a memory, the processor being configured to read instructions from the memory to execute the method according to any one of claims 1 to 11.

24. A wireless communication device, comprising a processor and a memory, the processor being configured to read instructions from the memory to execute the method according to any one of claims 12 to 22.

25. A non-transitory computer-readable medium, having stored thereon computer-executable instructions, which when executed by a processor are used to implement the method according to any one of claims 1 to 22.

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