Transmission device and method for performing block transmission in filter bank multicarrier ststem

Abstract

The present disclosure provides a transmission device and method comprising the steps of: phase-shifting, in a frequency domain, each phase of multiple symbols, upsampled by a factor of K according to an upsampling factor and filtered, on the basis of the order of symbols and the upsampling factor; and transmitting a transmission signal generated by combining the phase-shifted multiple symbols and performing an IFFT, and thus by cycle-shifting the location of transmitted symbols using phase shifters in a frequency domain before performing an IFFT, it is possible to perform block transmission with only a single IFFT, thus the device has low complexity and can be manufactured at low cost, and can be highly compatible with an OFDM system.

Description

Transmission method and device for performing block transmission in a filter bank multi-carrier system

[0001] The disclosed embodiments relate to a signal transmission method and apparatus of a wireless communication system, and more specifically, to a transmission method and apparatus for performing block transmission in a filter bank multi-carrier system.

[0002] Orthogonal Frequency Division Multiplexing (OFDM) systems have been widely used in wireless communication systems such as Long Term Evolution (LTE) and New Radio (NR). Because OFDM systems use rectangular waveforms in the time domain, they exhibit high Out-Of-Band Emission (OOBE) and require guard bands. Additionally, OFDM systems require Cyclic Prefixes (CPs) to prevent Inter-Symbol Interference (ISI) in frequency-selective channels. Due to the guard bands and CPs, OFDM systems have low transmission efficiency.

[0003] Filter Bank Multi-Carrier (FBMC) systems have been studied as an alternative to improve upon the shortcomings of CP-OFDM. FBMC systems utilize localized prototype filters in the time and frequency domains. Through localization in the time domain, FBMC systems possess robust characteristics for frequency-selective channels without CP. Additionally, localization in the frequency domain results in low OOBE. Consequently, FBMC systems exhibit higher spectral efficiency than OFDM systems.

[0004] However, while FBMC systems theoretically possess high transmission efficiency, this is limited to cases where the length of the transmitted signal is infinite. Since data is transmitted in packet units in actual systems, FBMC systems have transition time caused by upsampling in the frequency domain and overlapping in the time domain. Transition time poses a problem in that it severely degrades the transmission efficiency of FBMC systems, particularly during short packet transmissions.

[0005] The objective of the disclosed embodiments is to provide a transmission method and apparatus for performing block transmission by cyclically shifting the position of a symbol transmitted in the frequency domain using a phase shifter.

[0006] The objective of the disclosed embodiments is to provide a transmission method and apparatus that can reduce complexity by performing block transmission through a single IFFT module.

[0007] A transmission method according to an embodiment comprises: a step of phase-shifting each of a plurality of symbols that are upsampled by K times according to an upsampling factor in the frequency domain and filtered, based on the symbol order and the upsampling factor; and a step of transmitting a transmission signal generated by combining the phase-shifted plurality of symbols and then performing an IFFT.

[0008] The above multiple symbols can be applied as K, which is the same as the upsampling factor.

[0009] For the nth symbol (n = {1, …, K}) among the above K symbols, the phase can be shifted by 2π·n·(n-1) / K.

[0010] Each of the above multiple symbols can be composed of KM samples by upsampling the M parallelized symbols by K times according to the number of subcarriers (M).

[0011] A number of symbols upsampled by K times can be filtered by a convolution operation.

[0012] A number of phase-shifted and combined symbols can be converted into a number of FBMC signals by performing a KM-point IFFT according to an upsampling factor (K) and the number of subcarriers (M).

[0013] According to an embodiment, the transmitting device is a device comprising: a memory; and a processor that executes at least a portion of an operation according to a program stored in the memory,

[0014] The processor performs the steps of: phase-shifting each of a plurality of symbols that are upsampled by K times according to an upsampling factor in the frequency domain and filtered, based on the symbol order and the upsampling factor; and transmitting a transmission signal generated by combining the phase-shifted plurality of symbols and then performing an IFFT.

[0015] Accordingly, the transmission method and device according to the embodiment can perform block transmission with only a single IFFT by cyclically shifting the position of the transmitted symbol using a phase shifter in the frequency domain before performing the IFFT, so they can be manufactured with low complexity and low cost. In addition, since the filter bank and block transmission processes are all performed before the IFFT, they can be preprocessed in the same way as the preprocessing of existing OFDM systems, and the receiving device can also be postprocessed in the same way as the postprocessing method of OFDM systems, thus having high compatibility with OFDM systems.

[0016] Figure 1 shows the schematic structure of the transmitting and receiving devices of a conventional FBMC system.

[0017] Figure 2 is a diagram illustrating the overlap transmission and transition time of FBMC symbols in an FBMC system.

[0018] Figure 3 shows a simplified structure of an FBMC system that performs block transmission.

[0019] Figure 4 is a diagram illustrating the block transmission method of the transmitting device of Figure 3.

[0020] Figure 5 shows a schematic structure of an FBMC system according to one embodiment.

[0021] Figure 6 is a diagram illustrating the block transmission method of the transmitting device of Figure 5.

[0022] FIG. 7 illustrates a transmission method of an FBMC system according to one embodiment.

[0023] FIG. 8 is a drawing for explaining a computing environment including a computing device according to one embodiment.

[0024] Hereinafter, specific embodiments according to embodiments of the present disclosure will be described with reference to the drawings. The following detailed description is provided to facilitate a comprehensive understanding of the methods, apparatuses, and / or systems described herein. However, this is merely illustrative and the present invention is not limited thereto.

[0025] In describing the embodiments of the present disclosure, detailed descriptions of known technology related to the present invention are omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the embodiments. Furthermore, terms described below are defined with consideration of their functions in the present invention, and these may vary depending on the intentions or practices of the user or operator. Therefore, such definitions should be based on the content throughout this specification. Terms used in the detailed description are intended merely to describe specific embodiments and should not be limiting. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form. In this description, expressions such as “include” or “compose” are intended to refer to certain characteristics, numbers, steps, actions, elements, parts thereof, or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts thereof, or combinations thereof other than those described. Additionally, terms such as “...part,” “...unit,” “module,” and “block” described in the specification refer to a unit that processes at least one function or operation, and this may be implemented in hardware, software, or a combination of hardware and software.

[0026] Here, prior to describing the transmitting device for an FBMC system of one embodiment, the configuration and operation of a conventional FBMC system will be described for the sake of understanding.

[0027] Figure 1 shows the schematic structure of the transmitting and receiving devices of a conventional FBMC system, and Figure 2 is a diagram explaining the overlapping transmission and transition time of FBMC symbols in an FBMC system.

[0028] Referring to FIG. 1, the transmitting device may include a serial-to-parallel converter (11), an upsampling module (12), a prototype filter (13), an IFFT module (14), a parallel-to-serial converter (15), and an overlap module (16).

[0029] In FIG. 1, m (m ∈ {0, …, M-1}) represents the m-th subcarrier among M subcarriers, n (n ∈ {1, …, N}) represents the n-th FBMC symbol among the N transmitted FBMC symbols, and K represents the upsampling factor. d n [m] represents the QAM symbol transmitted as the m-th subcarrier of the n-th FBMC symbol.

[0030] The serial / parallel converter (11) is the nth QAM symbol (d n [m]) is received and parallelized into M, and M QAM symbols (d n = [d n [0], … , d n [M-1]]) is divided into. The upsampling module (12) has M QAM symbols (d n = [d n [0], … , d n [M-1]]) Each is upsampled by a factor of K to obtain KM samples. The prototype filter (13) performs filtering on the KM samples in the frequency domain through a convolution operation. The KM samples filtered by the prototype filter (13) are subjected to a KM-point inverse fast Fourier transformation (hereinafter IFFT) in the IFFT module (14) and modulated into an orthogonal subcarrier to form the nth FBMC signal (x n[i], where i ∈ {1, … M}) is obtained. Here, for convenience, only one upsampling module (12), one prototype filter (13), and one IFFT module (14) are shown, but M upsampling modules (12), M prototype filters (13), and M IFFT modules (14) are provided, and M parallelized nth QAM symbols (d n = [d n [0], … , d n From [M-1]]) the nth FBMC signal(x n [i]) obtain

[0031] nth FBMC signal(x n [i]) is upsampled K times in the frequency domain, so in the time domain, as shown in FIG. 2, it is transmitted K times repeatedly, which reduces the transmission rate by 1 / K times. Here, it is assumed that the upsampling factor (K) is 4 (K = 4) and the number of subcarriers to be transmitted is also 4 (M = 4). Accordingly, as shown in FIG. 2, each of the four FBMC signals (x1[i], …, x4[i]) output from the prototype filter (13) is a previous FBMC signal (x n-1 [i]) is output sequentially delayed by a sample interval. The overlap module (16) overlaps and combines the FBMC signals (x1[i], …, x4[i]) that are output sequentially delayed to form a transmission signal (x[i]).

[0032] The receiving device may include a parallel / serial converter (21), a downsampling module (22), a matched filter (23), an FFT module (24), a serial / parallel converter (25), and a window module (16) corresponding to the transmitting device.

[0033] The receiving device receives the received signal (r[i]) transmitted through the channel as the transmitted signal (x[i]). The receiving device receives the QAM symbol (d nBy performing the process of generating the transmitted signal (x[i]) from [m] in reverse, the QAM symbol (d) from the received signal (r[i]) n Acquire [m]).

[0034] First, the window module (26) receives the FBMC signal (x) corresponding to each subcarrier in the authorized received signal (r[i]). n [i]) distinguishes the FBMC signal. And the serial / parallel converter (25) distinguishes the FBMC signal (x n [i]) parallelizes, and the FFT module (24) parallelizes the FBMC signal (x n [i]) is converted into a frequency domain symbol by performing a KM-point fast Fourier transformation (hereinafter FFT). Then, a matched filter (23) corresponding to the prototype filter (13) performs filtering on the frequency domain symbol to match it. A downsampling module (22) downsamples the matched signal by a factor of k, and a parallel / serial converter (21) serializes the downsampled symbol to obtain a QAM symbol ( Restores ).

[0035] In a conventional FBMC system, the transmitting device, as shown in FIG. 2, provides an FBMC signal (x n [i]) are sequentially delayed and superimposed to form a transmission signal (x[i]), so the transmission signal (x[i]) has a transition time corresponding to a size of (N-1)M. If the number of symbols (N) being transmitted is sufficiently large, the transition time does not have a significant effect on transmission efficiency, but as shown in FIG. 2, when short packets with a small number of symbols (N) are transmitted, it becomes a factor that significantly reduces transmission efficiency.

[0036] Figure 3 shows a simplified structure of an FBMC system that performs block transmission, and Figure 4 is a diagram for explaining the block transmission method of the transmitting device of Figure 3.

[0037] To prevent the transmission efficiency from being reduced due to the aforementioned transition time, the transmitting device and receiving device of the FBMC system shown in FIG. 3 further include a cyclic shifter (19, 29), and the rest of the configuration is the same as that of the transmitting device and receiving device shown in FIG. 1. Accordingly, the operation of the cyclic shifter (19, 29) is described here.

[0038] Referring to FIG. 4(a), the cyclic mover (19) in the transmitting device includes an FBMC signal (x) included in the transition time in the time domain. n [i]) is extracted. Figure 4(a) illustrates the case where the last repeating signal of the 2nd FBMC signal (x2[i]), the two repeating signals of the 3rd FBMC signal (x3[i]), and the three repeating signals of the 4th FBMC signal (x4[i]) included in the transition time are extracted.

[0039] And as shown in FIG. 4(b), the cyclic mover (19) extracts the FBMC signal (x n [i]) is placed by cyclically shifting it to the initial position of each FBMC signal. Accordingly, the FBMC signal (x) cyclically shifted to the initial position n [i]) is overlapped across all intervals to form blocks, and the FBMC signal (x) composed of blocks n [i]) is superimposed and combined to generate a transmission signal (s[i]). As a result, the transmission efficiency can be significantly improved by excluding transition time from the transmission signal (s[i]).

[0040] The receiving device receives the receiving signal (r[i]) transmitted through the channel as the receiving signal (s[i]). Then, the circular mover (29) of the receiving device detects the signal circulated by the circular mover (19) of the transmitting device from the receiving signal (r[i]) and circulated it back to the end of the signal. That is, the signal circulated by the circular mover (19) of the transmitting device is circulated back to the transition time. When the signal circulated by the circular mover (19) of the transmitting device is circulated back to the transition time, this can be seen as the receiving signal (r[i]) transmitted by the transmitting device shown in FIG. 1 being received. Therefore, the receiving signal (r[i]) is processed in the same manner as before to obtain the QAM symbol (d n [m]) can be restored.

[0041] In the FBMC system of FIG. 3, the transmitting device uses a circular mover (19) to obtain an FBMC signal (x) included in the transition time in the time domain. n By circulating [i]) to the front of each signal, the FBMC signal (x n [i]) transmits a transmission signal (s[i]) that is nested in a block structure. Therefore, since no transition time is required, transmission efficiency can be increased even when the packet size is small.

[0042] However, in the FBMC system, since the circular mover (19, 29) is placed after the IFFT module (14) and the FFT module (24), there is a problem of significantly reduced compatibility with existing OFDM systems. In addition, in the transmitting device, the FBMC signal (x in the time domain) is generated by a plurality of IFFT modules (14). n[i]) After being converted, it is superimposed and combined, and since the signal received in the time domain is separated in the receiving device and then converted into the frequency domain, both the IFFT module (14) and the FFT module (24) are required as many times as the number of subcarriers (M), which causes a problem in that the complexity of the transmitting device and the receiving device increases significantly.

[0043] FIG. 5 shows a schematic structure of an FBMC system according to one embodiment, and FIG. 6 is a diagram for explaining the block transmission method of the transmitting device of FIG. 5.

[0044] Referring to FIG. 5, in an FBMC system of one embodiment, the transmitting device (30) includes a serial-to-parallel converter (31), an upsampling module (32), a prototype filter (33), an IFFT module (34), a parallel-to-serial converter (35), an overlap module (36), and a phase shifter (39).

[0045] Here, the serial / parallel converter (31), upsampling module (32), prototype filter (33), and phase shifter (39) may be provided in multiple numbers, and may be provided in numbers equal to the number of transmitted FBMC symbols (N). However, here, considering the upsampling factor (K), it is assumed that K FBMC symbols (N = K) are transmitted, and the upsampling factor (K) is assumed to be 4 (N = K = 4).

[0046] Accordingly, K serial / parallel converters (31) each have a corresponding QAM symbol (d1[m] ~ d K [m]) received as input, M QAM symbols (d n = [d n [0], … , d n[M-1]], where n = 1, … , K) is parallelized. Then, K upsampling modules (32) receive the output of K serial / parallel converters (31) and upsample it K times to obtain KM samples. The prototype filter (33) performs filtering on KM samples in the frequency domain through convolution operations. That is, the operation of the serial / parallel converters (31), upsampling modules (32), and prototype filters (33) performs the same operation as the serial / parallel converters (11), upsampling modules (12), and prototype filters (13) of the transmitting device shown in FIGS. 1 and FIGS. 3.

[0047] However, in the transmitting device illustrated in FIGS. 1 and 3, the IFFT module (14) performs a KM-point IFFT on KM samples filtered by the prototype filter (13) and modulates them into orthogonal subcarriers, thereby producing the nth FBMC signal (x) in the time domain. k [i], where i ∈ {1, … M}), was obtained. In contrast, in the transmitting device (30) illustrated in FIG. 5, K phase shifters (39) shift the phase of KM samples filtered by the prototype filter (33). Here, the phase shifter (39) shifts the phase by an amount equal to the phase change that occurs when the cyclic shifter (19) of FIG. 3 shifts cyclically as in FIG. 4. This is because the operation of the phase shifter (39) in the frequency domain operates identically to the operation of the cyclic shifter (19) in the time domain. Accordingly, in the transmitting device (30) of one embodiment, K phase shifters (39) each obtain an FBMC signal (x) included in the transition time. k [i]) shifts the phase of KM samples by the size of [i]. Specifically, the k-th phase shifter (39), which receives the n-th (here n = {1, …, K}) symbol, shifts the phase by 2π·n·(n-1) / K.

[0048] KM samples phase-shifted by K phase shifters (39) are superimposed by an overlap module (36). Then, an IFFT module (34) performs a KM-point IFFT on the frequency domain symbols superimposed by the overlap module (36) to modulate into orthogonal subcarriers in the time domain, thereby producing k FBMC signals (s) for each of the M subcarriers. k [i]) is obtained. And k FBMC signals (s k [i]) is converted into a serial signal to generate a transmission signal (s[i]), and the generated transmission signal (s[i]) is transmitted to a receiving device (40) through a channel.

[0049] That is, the transmitting device (30) illustrated in FIG. 5 includes a serial-to-parallel converter (31), an upsampling module (32), a prototype filter (33), an IFFT module (34), a parallel-to-serial converter (35), and an overlap module (36), just like the conventional transmitting device illustrated in FIG. 1; however, the IFFT module (34) performs a KM-point IFFT and, before converting to a signal in the time domain, uses a phase shifter (39) to first shift the phase of the symbol in the frequency domain, thereby producing an FBMC signal (x) in the time domain. k The trailing signal included in the transition time of [i]) is cyclically shifted to the FBMC signal (x k It is positioned at the front end of [i]). Thus, as shown in FIG. 6, a plurality of FBMC signals (s) that already constitute the transmitted signal (s[i]) in the frequency domain. k [i]) can be configured in a block form to eliminate transition time, thereby significantly improving transmission efficiency.

[0050] Then, after superimposing the phase-shifted symbols with the overlap module (36), the IFFT module (34) performs KM-point IFFT on the superimposed symbols in batches. Therefore, since the transmitting device (30) is equipped with only one IFFT module (34), complexity is significantly reduced and manufacturing costs are lowered. Also, in the time domain, the FBMC signal (x n Unlike the transmitting device of Fig. 3 which cycles the signal after [i]) is combined, the overlap module (36) first overlaps in the frequency domain and then converts to the time domain before the IFFT module (34) performs the KM-point IFFT, so high compatibility with the OFDM system can be maintained.

[0051] Here, the receiving device (40) also performs the reverse operation of the operation performed by the transmitting device (30), and may include the parallel / serial converter (41) and downsampling module (42), matched filter (43), FFT module (44) and serial / parallel converter (45) shown in FIG. 1, and further includes an equalizer (46) and a phase shifter (49).

[0052] Here, the parallel / serial converter (41), downsampling module (42), match filter (43), and phase shifter (49) may also be provided in multiple numbers, and may be provided in numbers equal to the number of transmitted FBMC symbols (N = K).

[0053] The serial / parallel converter (45) parallelizes the received signal (r[i]) to produce an FBMC signal (x k [i]) distinguishes, and multiple distinguished FBMC signals (x k[i]) is converted into multiple symbols in the frequency domain by performing a KM-point FFT with a single FFT module (44). Then, the equalizer (46) performs channel compensation according to the subcarrier in a configuration corresponding to the window module (26) in the receiving device of FIGS. 1 and 3, and distinguishes the symbols by frequency band of the subcarrier. Then, multiple phase shifters (49) restore the symbols transmitted by distinguishing by frequency band by shifting the phase shifted by the phase shifter (39) of the transmitting device back in the reverse direction. Then, the matching filter (43) performs filtering on the symbols in the frequency domain to match them, and the downsampling module (42) downsamples the matched signal by k times. Afterwards, the parallel / serial converter (41) serializes the downsampled symbols to QAM symbols ( Restores ).

[0054] Accordingly, the receiving device (40) also includes a parallel-to-serial converter (41), a downsampling module (42), a matched filter (43), an FFT module (44), and a serial-to-parallel converter (45), just like the conventional receiving device shown in FIG. 1, wherein a plurality of FBMC signals (x) parallelized in the serial-to-parallel converter (45) k For [i]), an FFT is performed using a single FFT module (44) to first convert it into a symbol in the frequency domain. Since only a single FFT module (44) is used, the complexity of the receiving device can be significantly reduced. In addition, high compatibility with the OFDM system can be maintained. However, since it is first converted into a symbol in the frequency domain, an equalizer (46) is used instead of a window module (26) to separate the symbol in the frequency domain, and the phase of the separated symbol is shifted using a plurality of phase shifters (49) to restore the shifted phase in order to remove the transition time from the transmitted signal (s[i]).

[0055] In the illustrated embodiments, each component may have different functions and capabilities in addition to those described above and may include additional components not described. Additionally, in one embodiment, each component may be implemented using one or more physically separated devices, or by one or more processors or a combination of one or more processors and software, and may not be clearly distinguished in specific operation as in the illustrated examples.

[0056] And the transmitting device illustrated in FIG. 5 may be implemented in a logic circuit by hardware, firmware, software, or a combination thereof, or may be implemented using a general-purpose or specific-purpose computer. The device may be implemented using a hardwired device, a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), etc. Additionally, the device may be implemented as a system-on-chip (SoC) including one or more processors and controllers.

[0057] In addition, the transmitting device may be mounted on a computing device or server equipped with hardware elements in the form of software, hardware, or a combination thereof. A computing device or server may refer to various devices that include, in whole or in part, communication devices such as communication modems for communicating with various devices or wired / wireless communication networks, memory for storing data for executing programs, and microprocessors for executing programs to perform calculations and commands.

[0058] FIG. 7 illustrates a transmission method of an FBMC system according to one embodiment.

[0059] Referring to FIG. 7, a transmission method of one embodiment first comprises a plurality of QAM symbols (d k[m]) Each is parallelized to a number corresponding to the number of subcarriers (71). Then, the parallelized QAM symbols are upsampled by K times according to the upsampling factor (K) to obtain KM samples (72). Subsequently, filtering is performed on the obtained KM samples using a convolution operation (73). Once the KM samples are filtered, phase shifting is performed on each of the K symbols, each consisting of M samples (74). Here, the phase shifting is intended to remove the transition time from the transmitted signal (s[i]) in the time domain by shifting the phase by a magnitude corresponding to the magnitude of the delay time caused by upsampling when the un-phase-shifted frequency domain symbol is converted into a time domain signal. Specifically, for the nth symbol (n = {1, …, K}) among the K symbols, the phase is shifted by 2π·n·(n-1) / K. Then, multiple phase-adjusted symbols are combined and superimposed (75). When multiple symbols overlap, a KM-point IFFT is performed on the overlapped symbols to obtain multiple FBMC signals (s) in the time domain. k [i]) is acquired in block form (76). Then, multiple FBMC signals (s k [i]) serializes the transmission signal (s[i]) and transmits it to the receiving device through the channel (77).

[0060] Although FIG. 7 describes each process as being executed sequentially, this is merely an illustrative description, and a person skilled in the art can apply various modifications and variations by changing the order described in FIG. 7, executing one or more processes in parallel, or adding other processes, within the scope of not departing from the essential characteristics of the embodiment of the present invention.

[0061] FIG. 8 is a drawing for explaining a computing environment including a computing device according to one embodiment.

[0062] In the illustrated embodiments, each component may have different functions and capabilities in addition to those described below, and may include additional components in addition to those described below. The illustrated computing environment (90) may include a computing device (91) to perform the transmission method illustrated in FIG. 7. In one embodiment, the computing device (91) may be one or more components included in the transmission device illustrated in FIG. 5.

[0063] A computing device (91) includes at least one processor (92), a computer-readable storage medium (93), and a communication bus (95). The processor (92) may enable the computing device (91) to operate according to the exemplary embodiment described above. For example, the processor (92) may execute one or more programs (94) stored in the computer-readable storage medium (93). The one or more programs (94) may include one or more computer-executable instructions, and the computer-executable instructions may be configured to enable the computing device (91) to perform operations according to the exemplary embodiment when executed by the processor (92).

[0064] The communication bus (95) interconnects various other components of the computing device (91), including the processor (92) and the computer-readable storage medium (93).

[0065] The computing device (91) may also include one or more input / output interfaces (96) and one or more communication interfaces (97) that provide an interface for one or more input / output devices (98). The input / output interfaces (96) and communication interfaces (97) are connected to a communication bus (95). The input / output devices (98) may be connected to other components of the computing device (91) through the input / output interfaces (96). An exemplary input / output device (98) may include an input device such as a pointing device (such as a mouse or trackpad), a keyboard, a touch input device (such as a touchpad or touchscreen), a voice or sound input device, various types of sensor devices and / or imaging devices, and / or an output device such as a display device, a printer, a speaker and / or a network card. An exemplary input / output device (98) may be included inside the computing device (91) as a component constituting the computing device (91), or it may be connected to the computing device (91) as a separate device distinct from the computing device (91).

[0066] Although the present invention has been described in detail above through representative embodiments, those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims.

Claims

1. A step of phase-shifting each of a plurality of symbols, which are upsampled by K times and filtered according to an upsampling factor in the frequency domain, based on the symbol order and the upsampling factor; and A transmission method of an FBMC system comprising the step of transmitting a transmission signal generated by combining a plurality of phase-shifted symbols and then performing an IFFT.

2. In Paragraph 1, A transmission method of an FBMC system in which the above-mentioned plurality of symbols are applied as K, which is the same as the upsampling factor.

3. In Paragraph 2, A transmission method of an FBMC system in which the phase of the n-th symbol (n = {1, …, K}) among the above K symbols is shifted by 2π·n·(n-1) / K.

4. In Paragraph 1, A transmission method of an FBMC system in which each of the above multiple symbols is composed of KM samples by upsampling M parallelized symbols according to the number of subcarriers (M).

5. In Paragraph 1, A transmission method of an FBMC system in which multiple symbols upsampled by K times are filtered by a convolution operation.

6. In Paragraph 1, A transmission method of an FBMC system in which a plurality of phase-shifted and combined symbols are KM-point IFFT-transformed according to an upsampling factor (K) and the number of subcarriers (M) to be converted into a plurality of FBMC signals.

7. In any one of paragraphs 1 to 6, the transmitting method of the FBMC system A transmission method of an FBMC system performed by the processor of a device including a memory and a processor.

8. A device comprising a memory; and a processor that executes at least a portion of an operation according to a program stored in the memory, The above processor A step of phase-shifting each of a plurality of symbols, which are upsampled by K times and filtered according to an upsampling factor in the frequency domain, based on the symbol order and the upsampling factor; and A transmitting device of an FBMC system that performs the step of transmitting a transmission signal generated by combining a plurality of phase-shifted symbols and then performing an IFFT.

9. In Paragraph 8, The above-mentioned plurality of symbols is a transmitting device of an FBMC system that is applied as K symbols equal to the upsampling factor.

10. In Paragraph 9, A transmitting device of an FBMC system that shifts the phase of the n-th symbol (n = {1, …, K}) among the above K symbols by 2π·n·(n-1) / K.

11. In Paragraph 8, A transmitting device of an FBMC system in which each of the above multiple symbols is composed of KM samples by upsampling M parallelized symbols according to the number of subcarriers (M).

12. In Paragraph 8, A transmitting device of an FBMC system in which multiple symbols upsampled by K times are filtered by a convolution operation.

13. In Paragraph 8, A transmitting device of an FBMC system in which a plurality of phase-shifted and combined symbols are KM-point IFFT-transformed according to an upsampling factor (K) and the number of subcarriers (M) to be converted into a plurality of FBMC signals.

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