Discrete carrier flexible aggregation method, device and system

Abstract

The invention provides a discrete carrier flexible aggregation method, device and system, and relates to the technical field of power system communication, and the method comprises the steps: determining that the sub-carrier interval in a discrete carrier is 2.5 * n kHz, and n is 0.5, 1, 2 or 4; idle discrete carriers in discrete carriers of the discrete narrowband wireless system are detected, and physical continuous idle discrete carriers are flexibly aggregated to form a carrier cluster; dividing the carrier cluster into a plurality of mutually orthogonal subcarriers according to subcarrier intervals, and modulating data to be sent to the subcarriers by adopting an OFDM (Orthogonal Frequency Division Multiplexing) multi-carrier technology; independently filtering all the carrier clusters based on a filter to obtain filtered carrier clusters; the filtering parameter of the filter is related to the number of idle discrete carriers in the carrier cluster; and transmitting the to-be-sent data modulated to the subcarrier through the filtered carrier cluster. Under the condition that the special frequency band resources are limited, the edge resources of the carrier bandwidth are fully utilized through the discrete carrier aggregation technology, the higher frequency spectrum utilization rate is obtained, and the transmission capacity and quality of the system are improved.

Description

Technical Field

[0001] The present invention relates to the field of power system communication technology, and in particular to a discrete carrier flexible aggregation method, device and system. Background Art

[0002] A large number of distributed sources and loads such as new power systems, distributed renewable energy, and flexible controllable loads are connected to the power grid. Due to the constraints of economy and access flexibility, optical fiber communication is difficult to meet the requirements, and wireless communication must be used to strengthen the interaction between sources, grids, loads and storage. The security and real-time nature of wireless communication directly affect the safe and stable operation of the power grid, which is difficult to meet with wireless public networks. There is an urgent need to efficiently use power-specific frequency bands to achieve safe and real-time carrying of massive control-related services. There are two types of wireless private network technology systems in the existing technology, namely LTE-G (Long Term Evolution) 230MHz and IOT-G (Internet of Things-Grid) 230MHz, two 230MHz wireless private network technology systems, but both of the above technical systems have some shortcomings.

[0003] The frame structure length of LTE-G 230MHz is 25ms, and the subcarrier spacing within each carrier is 2KHz. Under this technical system, the frame structure is relatively long, which cannot meet the low-latency transmission requirements of power services, and the spectrum utilization rate is not high. In addition, in the case of multi-carrier aggregation, the protection interval of adjacent carriers cannot be reused, and thus the spectrum utilization rate under multi-carrier aggregation cannot be improved. The frame structure length of IOT-G 230MHz is 10ms, and the subcarrier spacing within each carrier is 3.75KHz. Due to the 25kHz working bandwidth limit of the National Radio and Television Commission on the 30MHz frequency band, edge subband filtering will cause large signal energy loss or distortion, poor transmission signal quality, and poor system spectrum efficiency and anti-interference ability. In addition, in the case of multi-carrier aggregation, the edge subband quality is greatly affected by the filter. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, in a first aspect, the present invention provides a discrete carrier flexible aggregation method, which is applied to a discrete narrowband wireless system with an operating frequency band of 223-235 MHz and a carrier bandwidth of 25 KHz, and adopts orthogonal frequency division multiplexing OFDM multi-carrier technology for transmission, comprising:

[0005] Determine that the subcarrier spacing in the discrete carrier is 2.5*n kHz, where n is 0.5, 1, 2 or 4;

[0006] Detecting idle discrete carriers in discrete narrowband wireless system discrete carriers, and flexibly aggregating physically continuous idle discrete carriers to form a carrier cluster;

[0007] The carrier cluster is divided into multiple mutually orthogonal subcarriers according to the subcarrier spacing, and the data to be sent is modulated onto the subcarriers using OFDM multicarrier technology;

[0008] All carrier clusters are individually filtered based on the filter to obtain a filtered carrier cluster; a filtering parameter of the filter is related to the number of idle discrete carriers in the carrier cluster;

[0009] The data to be sent modulated onto the subcarriers is transmitted via the filtered carrier cluster.

[0010] Optionally, the value range of the number of physically continuous idle discrete carriers included in the carrier cluster is [1, 159].

[0011] Optionally, when the subcarrier spacing in the discrete carrier is 2.5 kHz and the number of physically continuous idle discrete carriers in the carrier cluster is 1, the number of subcarriers in the carrier cluster is 7 or 9.

[0012] Optionally, when the subcarrier spacing in the discrete carrier is 2.5kHz and the number of physically continuous idle discrete carriers in the carrier cluster is greater than or equal to 1, the number of subcarriers in the carrier cluster is 10*N Subband -3 or 10*N Subband -1, N Subband is the number of physically continuous idle discrete carriers in the carrier cluster, 1≤N Subband ≤159.

[0013] Optional, when the number of subcarriers in the carrier cluster is 10*N Subband -3, the modulation mode of OFDM multi-carrier technology is 64QAM or 256QAM.

[0014] Optionally, when the number of subcarriers in the carrier cluster is 9, the modulation mode of the OFDM multi-carrier technology is QPSK, 16QAM or 64QAM.

[0015] Optional, when N Subband ≠1, and the number of subcarriers in the carrier cluster is 10*N Subband -1, the modulation mode of OFDM multi-carrier technology is 64QAM or 256QAM.

[0016] Optionally, the filter parameters of the filter include: sampling rate, cutoff frequency, passband frequency, passband ripple depth, stopband attenuation;

[0017] The filter parameter value of the filter is: sampling rate 2.5e3*N FFT , cut-off frequency 25e3*N Subband / 2, passband frequency 25e3*N Subband / 2-0.7e3, passband ripple depth 0.2dB, stopband attenuation 40dB, where NFFT is the number of Fourier sampling points, N Subband is the number of physically continuous idle discrete carriers in the carrier cluster.

[0018] Optionally, the discrete narrowband wireless system includes multiple carrier clusters, and the total number of idle discrete carriers included in the multiple carrier clusters is in the range of [1, 278];

[0019] The total number of subcarriers included in the multiple carrier clusters is 10*N′ Subband -3 or 10*N′ Subband -1, N′ Subband is the total number of idle discrete carriers contained in multiple carrier clusters, 1≤N′ Subband ≤278.

[0020] In a second aspect, the present invention further provides a communication device, comprising:

[0021] A processing module, used for determining that the subcarrier spacing in the discrete carrier is 2.5*n kHz, where n is 0.5, 1, 2 or 4;

[0022] Detecting idle discrete carriers in discrete narrowband wireless system discrete carriers, and flexibly aggregating physically continuous idle discrete carriers to form a carrier cluster;

[0023] Dividing the carrier cluster into a plurality of mutually orthogonal subcarriers according to the subcarrier spacing, and modulating the data to be transmitted onto the subcarriers using OFDM multicarrier technology;

[0024] All carrier clusters are individually filtered based on the filter to obtain a filtered carrier cluster; a filtering parameter of the filter is related to the number of idle discrete carriers in the carrier cluster;

[0025] The communication module is used to transmit the data to be sent modulated to the subcarrier through the filtered carrier cluster.

[0026] In a third aspect, the present invention further provides a discrete carrier flexible aggregation method, which is applied to a discrete narrowband wireless system with an operating frequency band of 223-235 MHz and a carrier bandwidth of 25 KHz, and adopts orthogonal frequency division multiplexing OFDM multi-carrier technology for transmission, comprising:

[0027] receiving data to be received;

[0028] Perform matched filtering and OFDM demodulation processing on the received data to obtain processed data;

[0029] The data to be received is to determine that the subcarrier spacing in the discrete carrier is 2.5*n kHz, where n is 0.5, 1, 2 or 4; detect the idle discrete carriers in the discrete carriers of the discrete narrowband wireless system, flexibly aggregate the physically continuous idle discrete carriers to form a carrier cluster; divide the carrier cluster into multiple mutually orthogonal subcarriers according to the subcarrier spacing, and use OFDM multi-carrier technology to modulate the data to be sent to the subcarriers; based on the filter, all carrier clusters are individually filtered to obtain the filtered carrier cluster; the filtering parameters of the filter are related to the number of idle discrete carriers in the carrier cluster; and the carrier cluster is modulated to the subcarrier through the filtered carrier cluster transmission.

[0030] In a fourth aspect, the present invention further provides a communication device, comprising:

[0031] A communication module, used for acquiring received data;

[0032] The processing module is used to perform matched filtering and OFDM demodulation processing on the data to be received to obtain the processed data; the data to be received is to determine that the subcarrier interval in the discrete carrier is 2.5*n kHz, and n is 0.5, 1, 2 or 4; detect the idle discrete carriers in the discrete carriers of the discrete narrowband wireless system, and flexibly aggregate the physically continuous idle discrete carriers to form a carrier cluster; divide the carrier cluster into multiple mutually orthogonal subcarriers according to the subcarrier interval, and use OFDM multi-carrier technology to modulate the data to be sent to the subcarrier; based on the filter, all carrier clusters are individually filtered to obtain the filtered carrier cluster; the filtering parameters of the filter are related to the number of idle discrete carriers in the carrier cluster; and the data is obtained after being modulated to the subcarrier through the filtered carrier cluster transmission.

[0033] In a fifth aspect, the present invention further provides a communication system, comprising a transmitting end and a receiving end; the transmitting end is used to implement the discrete carrier flexible aggregation method described in the first aspect above, and the receiving end is used to implement the discrete carrier flexible aggregation method described in the third aspect above.

[0034] In a sixth aspect, the present invention further provides an electronic device, comprising: at least one processor and a memory; the memory and the processor are connected via a bus;

[0035] The memory is used to store one or more programs;

[0036] When the one or more programs are executed by the at least one processor, the discrete carrier flexible aggregation method as described in the first aspect above is implemented, or the discrete carrier flexible aggregation method as described in the third aspect above is implemented.

[0037] In a seventh aspect, the present invention further provides a readable storage medium having an execution program stored thereon. When the execution program is executed, the discrete carrier flexible aggregation method as described in the first aspect above is implemented, or the discrete carrier flexible aggregation method as described in the third aspect above is implemented.

[0038] Compared with the closest prior art, the present invention has the following beneficial effects:

[0039] The present invention provides a discrete carrier flexible aggregation method, which is applied to a discrete narrowband wireless system with a working frequency band of 223-235MHz and a carrier bandwidth of 25KHz, and adopts orthogonal frequency division multiplexing OFDM multi-carrier technology for transmission, including: determining that the subcarrier interval in the discrete carrier is 2.5*n kHz, where n is 0.5, 1, 2 or 4; detecting idle discrete carriers in discrete carriers of the discrete narrowband wireless system, and flexibly aggregating physically continuous idle discrete carriers to form a carrier cluster; dividing the carrier cluster into a plurality of mutually orthogonal subcarriers according to the subcarrier interval, and modulating the data to be sent to the subcarrier using OFDM multicarrier technology; filtering all carrier clusters separately based on a filter to obtain a filtered carrier cluster; the filtering parameters of the filter are related to the number of idle discrete carriers in the carrier cluster; and transmitting the data to be sent modulated to the subcarrier through the filtered carrier cluster. In the case of limited dedicated frequency band resources, the present invention makes full use of the edge resources of the carrier bandwidth through discrete carrier aggregation technology to obtain higher spectrum utilization and improve the system transmission capacity and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of the process of the discrete carrier flexible aggregation method provided by the present invention;

[0041] Figure 2 A schematic diagram of a single-carrier working state provided by the present invention including 7 subcarriers;

[0042] Figure 3 It is a schematic diagram of subcarriers included in the multi-carrier aggregation working condition (when a single carrier includes 7 subcarriers) provided by the present invention.

[0043] Figure 4 A schematic diagram of a single-carrier working state provided by the present invention including 9 subcarriers;

[0044] Figure 5 It is a schematic diagram of subcarriers included in the multi-carrier aggregation working condition (when a single carrier includes 9 subcarriers) provided by the present invention.

[0045] Figure 6 It is a schematic diagram of subcarrier distribution in the case of single carrier operation of LTE-G 230MHz in the prior art;

[0046] Figure 7 It is a schematic diagram of the distribution of subcarriers in the case of single carrier operation of IOT-G 230MHz in the prior art;

[0047] Figure 8 This is a block diagram of the EVM test link for the direct transmission scenario provided by the present invention;

[0048] Fig. 9 It is a received signal constellation diagram of LTE-G 230MHz in the prior art;

[0049] Fig.10 A constellation diagram of received signals of the discrete carrier flexible aggregation method provided by the present invention;

[0050] Fig.11 It is the receiving signal constellation diagram of IOT-G 230MHz in the prior art;

[0051] Fig.12 A schematic diagram of the structure of the communication system provided by the present invention;

[0052] Fig.13 A schematic diagram of the structure of a communication device provided by the present invention;

[0053] Fig.14 This is a schematic structural diagram of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0054] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0055] Embodiment 1:

[0056] The present invention provides a discrete carrier flexible aggregation method, which is applied to a discrete narrowband wireless system with an operating frequency band of 223-235 MHz and a carrier bandwidth of 25 KHz, and adopts OFDM (Orthogonal Frequency Division Multiplexing) multi-carrier technology transmission. Specifically, Figure 1 A flow chart of a discrete carrier flexible aggregation method provided in an embodiment of the present invention includes the following steps as shown in the figure:

[0057] S1: The transmitter determines that the subcarrier spacing in the discrete carrier is 2.5*n kHz, where n is 0.5, 1, 2, or 4;

[0058] S2: The transmitter detects idle discrete carriers in the discrete narrowband wireless system discrete carriers, and flexibly aggregates physically continuous idle discrete carriers to form a carrier cluster;

[0059] S3: The transmitter divides the carrier cluster into multiple mutually orthogonal subcarriers according to the subcarrier spacing, and modulates the data to be sent onto the subcarriers using OFDM multicarrier technology;

[0060] S4: The transmitting end performs individual filtering on all carrier clusters based on the filter to obtain a filtered carrier cluster; the filtering parameter of the filter is related to the number of idle discrete carriers in the carrier cluster;

[0061] S5: The transmitting end transmits the data to be transmitted modulated to the subcarrier through the filtered carrier cluster, and correspondingly, the receiving end receives the data to be received;

[0062] S6: The receiving end performs matched filtering and OFDM demodulation processing on the data to be received to obtain processed data.

[0063] In the case of limited dedicated frequency band resources, the present invention fully utilizes edge resources of carrier bandwidth through discrete carrier aggregation technology to obtain higher spectrum utilization and improve system transmission capacity and quality.

[0064] According to the current 230MHz allocation policy, the power industry has a total of 7MHz resources available. In the working frequency band of 223-235MHz, the power industry can use the frequency bands of 223-226MHz and 229-233MHz, and its carrier bandwidth is 25KHz. In the present invention, the carrier bandwidth of 25KHz is called narrowband, and OFDM multi-carrier technology is used for transmission.

[0065] In the embodiment of the present invention, the subcarrier spacing in the discrete carrier is determined to be 2.5*nkHz, where n is 0.5, 1, 2 or 4. That is, in a carrier bandwidth of 25KHz, the subcarrier spacing of the discrete carrier can be set to 1.25KHz, 2.5KHz, 5KHz or 10KHz, which is more suitable for data communication performance at 25KHz discrete frequency points in the 230MHz frequency band. The 230MHz frequency band is characterized by being composed of a number of sporadic and discrete narrowband frequency resources.

[0066] In the subsequent introduction of the present invention, the discrete carrier subcarrier spacing of 2.5KHz is used for expansion. The discrete carrier flexible aggregation method of the remaining subcarrier spacings is the same as that of 2.5KHz, and can be aggregated with reference to the subcarrier spacing of 2.5KHz, which will not be described one by one in the subsequent description.

[0067] After determining the subcarrier spacing in the discrete carrier, the idle discrete carriers in the discrete narrowband wireless system are detected, and the physically continuous idle discrete carriers are flexibly aggregated to form a carrier cluster. Since the frequency bands available for the power industry are 223-226MHz and 229-233MHz, that is, 3MHz+4MHz. Based on the carrier bandwidth of 25KHz, if all discrete carriers in the discrete narrowband wireless system are idle discrete carriers, the number of physically continuous idle discrete carriers N contained in a carrier cluster is Subband The maximum value is 159. That is, the number of physically continuous idle discrete carriers contained in a single carrier cluster is N Subband The value range is [1, 159].

[0068] In the embodiment of the present invention, there may be multiple carrier clusters formed by flexible aggregation of physically continuous idle discrete carriers, which can be more suitable for physically discontinuous idle discrete carriers, because the idle discrete carriers are not necessarily all physically continuous. In a specific example, it may be detected that discrete carriers No. 1-40, No. 47, and No. 55-70 are idle discrete carriers, then these three idle discrete carriers can form three carrier clusters.

[0069] The frequency band available for the power industry is 7 MHz. When a discrete narrowband wireless system contains multiple carrier clusters, the total number of idle discrete carriers contained in the multiple carrier clusters is N. S ' ubband The maximum value of is 278, that is, the total number N of idle discrete carriers contained in the multiple carrier clusters S ' ubband The value range is [1, 278].

[0070] After the carrier cluster is formed, the carrier cluster is divided into multiple mutually orthogonal subcarriers according to the subcarrier spacing, and the data to be sent is modulated onto the subcarriers using OFDM multi-carrier technology.

[0071] Orthogonal frequency division multiplexing (OFDM) is a multi-carrier modulation technology and also a FDM (Frenquency Division Multiplexing) system. In the traditional frequency division method, the carrier is divided into several non-overlapping sub-carriers to transmit parallel data streams. A set of filters is used at the receiving end to separate the sub-channels, and a protection band must be left between the sub-channels. Therefore, this method has low bandwidth utilization. OFDM consists of a large number of sub-carriers that are equally spaced in frequency. The spectra of these sub-carriers can overlap with each other, which greatly improves the spectrum utilization. In addition, the sub-carriers are orthogonal to each other over the entire symbol period, that is, the product integral of any two sub-carriers over the symbol period is equal to zero. In this way, even if there is overlap between the sub-carrier spectra, they can be restored without distortion.

[0072] Specifically, in a specific implementation of the present invention, when the subcarrier spacing in a discrete carrier is 2.5 KHz and the number of physically continuous idle discrete carriers in a carrier cluster is 1, that is, in a single carrier operation case, the number of subcarriers in the carrier cluster is 7 or 9.

[0073] When the subcarrier spacing in a discrete carrier is 2.5KHz and the number of physically continuous idle discrete carriers in a carrier cluster is greater than or equal to 1, the number of subcarriers in a single carrier cluster is 10*N Subband -3 or 10*N Subband -1, N Subband is the number of physically continuous idle discrete carriers in the carrier cluster, 1≤N Subband ≤159.

[0074] Specifically, when the number of physically continuous idle discrete carriers in the carrier cluster is N Subband When the number of subcarriers in a single carrier is 7, the corresponding number of subcarriers N SC The calculation formula is as follows:

[0075] N SC =10×N Subband -3

[0076] Or, when the number of physically continuous idle discrete carriers in the carrier cluster is N Subband When the number of subcarriers in a single carrier is 9, the corresponding number of subcarriers N SC The calculation formula is as follows:

[0077] N SC =10×N Subband -1

[0078] like Figure 2 As shown, it is a schematic diagram of the present invention including 7 subcarriers under the single carrier working condition. According to the calculation method of the transmission bandwidth of 3GPP (3rd Generation Partnership Project, the third generation partnership project), the spectrum utilization rate under the single carrier working condition = transmission bandwidth / carrier bandwidth, transmission bandwidth = effective number of subcarriers * subcarrier spacing, the transmission bandwidth under the single carrier of the present invention = 7*2.5 = 17.5KHz, and the spectrum utilization rate = 17.5 / 25 = 70%.

[0079] like Figure 3 As shown, it is a schematic diagram of subcarriers included in the case of multi-carrier aggregation working of the present invention (when a single carrier includes 7 subcarriers).

[0080] When a single carrier contains 7 subcarriers, when two carriers are continuously aggregated, 3 subcarriers can be added to the adjacent parts of the two carriers, that is, when the carrier bandwidth is 25KHz*2, there are 7*2+3=17 subcarriers. When the number of physically continuous idle discrete carriers in the carrier cluster is 2, the number of subcarriers in the carrier cluster is 10*2-3=17. The transmission bandwidth when two carriers are continuously aggregated is 17*2.5=42.5KHz, and the spectrum utilization rate = 42.5 / 25*2=85%.

[0081] When a single carrier contains 7 subcarriers, when 3 carriers are continuously aggregated, 6 subcarriers can be added to the adjacent parts of the 3 carriers, that is, when the carrier bandwidth is 25KHz*3, there are 7*3+6=27 subcarriers. When the number of physically continuous idle discrete carriers in the carrier cluster is 3, the number of subcarriers in the carrier cluster is 10*3-3=27. The transmission bandwidth when 3 carriers are continuously aggregated is 27*2.5=67.5KHz, and the spectrum utilization rate is 67.5 / 25*3=90%. The transmission bandwidth when 4 carriers are continuously aggregated is 37*2.5=92.5KHz, and the spectrum utilization rate is 92.5 / 25*4=92.5%.

[0082] Similarly, when the number of physically continuous idle discrete carriers in the carrier cluster is N Subband When (N Subband -1)*3 subcarriers, the number of subcarriers in a carrier cluster is 10*N Subband -3 pieces.

[0083] As the number of physically continuous idle discrete carriers N in the carrier cluster increases Subband With the increase of the number of carriers, the spectrum utilization rate gradually increases when multiple carriers are continuously aggregated. Considering that the maximum number of physically continuous idle discrete carriers contained in a single carrier cluster in the power industry is 159, the maximum spectrum utilization rate is: (10*159-3)*2.5 / 25*159=99.81%.

[0084] like Figure 4 As shown, it is a schematic diagram of a single carrier working condition of the present invention including 9 subcarriers. According to the calculation method of transmission bandwidth of 3GPP, the transmission bandwidth under a single carrier is 9*2.5=22.5KHz, and the spectrum utilization rate=22.5 / 25=90%.

[0085] like Figure 5 As shown, it is a schematic diagram of subcarriers included in the case of multi-carrier aggregation working of the present invention (when a single carrier includes 9 subcarriers).

[0086] When a single carrier contains 9 subcarriers, when two carriers are continuously aggregated, one subcarrier can be added to the adjacent parts of the two carriers, that is, when the carrier bandwidth is 25KHz*2, there are 9*2+1=19 subcarriers. When the number of physically continuous idle discrete carriers in the carrier cluster is 2, the number of subcarriers in the carrier cluster is 10*2-1=19. The transmission bandwidth when two carriers are continuously aggregated is 19*2.5=47.5KHz, and the spectrum utilization rate = 47.5 / 25*2=95%.

[0087] When a single carrier contains 9 subcarriers, when 3 carriers are continuously aggregated, 2 subcarriers can be added to the adjacent parts of the 3 carriers, that is, when the carrier bandwidth is 25KHz*3, there are 9*3+2=29 subcarriers in total. When the number of physically continuous idle discrete carriers in the carrier cluster is 3, the number of subcarriers in the carrier cluster is 10*3-1=29. The transmission bandwidth when 3 carriers are continuously aggregated is 29*2.5=72.5KHz, and the spectrum utilization rate = 72.5 / 25*3=96.67%. Similarly, when the number of physically continuous idle discrete carriers in the carrier cluster is N Subband When N Subband -1 subcarrier, the number of subcarriers in a carrier cluster is 10*N Subband -1 pc.

[0088] As the number of physically continuous idle discrete carriers N in the carrier cluster increases Subband With the increase of the number of carriers, the spectrum utilization rate gradually increases when multiple carriers are continuously aggregated. Considering that the maximum number of physically continuous idle discrete carriers contained in a single carrier cluster in the power industry is 159, the maximum spectrum utilization rate is: (10*159-1)*2.5 / 25*159=99.94%.

[0089] In the case of continuous carrier aggregation, the spectrum utilization rate can theoretically reach 100%. However, considering the filtering effect of the subsequent filter, the two edge subcarriers are affected by the filter and the performance will suffer a certain loss. The modulation method can be reduced to meet the requirements of system design.

[0090] Optionally, since the frequency band available for the power industry is 7 MHz, multiple carrier clusters are formed, and the total number of subcarriers included in the multiple carrier clusters is 10*N′ Subband -3 or 10*N′ Subband -1, N′ Subband is the total number of idle discrete carriers contained in multiple carrier clusters, 1≤N′ Subband ≤278.

[0091] The maximum total number of idle discrete carriers contained in the current multiple carrier clusters in the power industry is 278. In an ideal case, the spectrum utilization rate is (278*10-3)*2.5 / (25*278)=99.892%.

[0092] EVM is the vector difference between an ideal error-free reference signal and the actual transmitted signal at a given moment. This vector difference can comprehensively measure the amplitude error and phase error of the modulated signal.

[0093] When the number of subcarriers in a carrier cluster is 10*N Subband -3, the modulation mode of OFDM multi-carrier technology is 64QAM or 256QAM. Specifically, according to the simulation results, in the case of single carrier 256QAM, EVM < 3.5%, which meets the design requirements of the wireless system, and the modulation mode of the subcarrier can be orthogonal amplitude modulation 64QAM or 256QAM.

[0094] When the number of subcarriers in the carrier cluster is 9, the modulation mode of OFDM multicarrier technology is QPSK, 16QAM or 64QAM. Specifically, according to the simulation results, under the single-carrier 64QAM working condition, the average EVM of the middle subcarrier is less than 1.9%, and the average EVM of the edge subcarrier is less than 8%. The modulation mode of the subcarrier can be orthogonal amplitude modulation QPSK, 16QAM or 64QAM.

[0095] When N Subband ≠1, and the number of subcarriers in the carrier cluster is 10*N Subband -1, the modulation mode of OFDM multi-carrier technology is 64QAM or 256QAM. According to the simulation results, the average EVM of the middle subcarrier is less than 1.4%, and the average EVM of the edge subcarrier is less than 5%. The modulation mode of the subcarrier can be orthogonal amplitude modulation 64QAM or 256QAM.

[0096] In the present invention, the modulation mode of the OFDM multi-carrier technology is selected according to the number of sub-carriers in the carrier cluster.

[0097] Specifically, QAM (Quadrature Amplitude Modulation) is a method of modulating a signal by both amplitude and phase, with amplitude and phase changing simultaneously, and is a non-constant envelope two-dimensional modulation. QAM is a combination of orthogonal carrier modulation technology and multi-level amplitude keying.

[0098] Among them, 16QAM (16-Quadrature Amplitude Modulation) is a 16-order quadrature amplitude modulation. Each OFDM symbol can represent 4 bits of data. There are 4 amplitude and 4 phase combinations, and 16 different symbol states are used.

[0099] 64QAM (64-Quadrature Amplitude Modulation) is a 64-order quadrature amplitude modulation. Each OFDM symbol can represent 6 bits of data. There are 6 amplitude and 6 phase combinations, using 64 different symbol states.

[0100] 256QAM (256-QuadratureAmplitude Modulation) is a 256-order quadrature amplitude modulation. Each OFDM symbol can represent 8 bits of data. There are 8 amplitude and 8 phase combinations, using 256 different symbol states.

[0101] QPSK (Quadrature Phase Shift Keying) is an extended form of BPSK (Binary Phase Shift Keying). Each OFDM symbol transmits 2 bits of data and represents the data through 4 different phases. QPSK uses 4 phases, with each 90 degrees as a phase interval, representing the four bit combinations of 00, 01, 10, and 11.

[0102] Regarding the number of subcarriers in a carrier cluster, those skilled in the art may select an appropriate modulation method according to actual requirements, and no limitation is imposed here.

[0103] All carrier clusters are filtered separately based on the filter to obtain filtered carrier clusters; the filtering parameters of the filter are related to the number of idle discrete carriers in the carrier cluster.

[0104] Specifically, each carrier cluster is filtered individually based on the filtering parameters of the filter. The filtering parameters of the filter used in the present invention are shown in Table 1.

[0105]

[0106] Table 1

[0107] Among them, N FFT is the number of Fourier sampling points, N Subband is the number of physically continuous idle discrete carriers in the carrier cluster. When transmitting data at the same time, if there are multiple carrier clusters transmitting, the filtering parameters for filtering multiple carrier clusters may not be the same. The filtering parameters are related to the number of idle discrete carriers in the carrier cluster. For different carrier clusters, the length of the filter is related to N. FFT The ratio is the same, and the amount of carrier filtering calculation is proportional to the size of the flexible aggregated carrier cluster.

[0108] The data to be sent modulated onto the subcarriers is transmitted via the filtered carrier cluster.

[0109] The technical effect of the discrete carrier flexible aggregation method provided by the present invention is described in detail below in combination with the prior art LTE-G 230MHz and IOT-G230MHz.

[0110] Figure 6 This is a schematic diagram of the distribution of subcarriers in the case of single carrier operation of LTE-G 230MHz in the prior art. Figure 6 LTE-G 230MHz is introduced.

[0111] The frame structure length of LTE-G 230MHz is 25ms. It adopts orthogonal frequency division multiplexing OFDM multi-carrier technology for transmission. The carrier bandwidth is 25KHz. The subcarrier spacing in single-carrier operation is 2KHz. 11 subcarriers are deployed in each carrier bandwidth, and the carrier bandwidth is 24KHz. In the case of multi-carrier aggregation, the protection interval between adjacent carriers is 0.5KHz. According to the calculation method of transmission bandwidth of 3GPP (3rd Generation Partnership Project), the spectrum utilization rate in single-carrier operation = transmission bandwidth / carrier bandwidth, transmission bandwidth = number of effective subcarriers * subcarrier spacing, LTE-G 230MHz transmission bandwidth = 11*2 = 22KHz, spectrum utilization = 22 / 25 = 88%.

[0112] In the case of multi-carrier aggregation, since the subcarrier spacing of the LTE-G 230MHz system is 2KHz, the guard interval of adjacent carriers is only 0.5KHz. The guard interval in the case of multi-carrier aggregation is much smaller than the subcarrier spacing, so the guard interval between adjacent carriers cannot be reused. Therefore, the spectrum utilization rate remains unchanged in the case of multi-carrier aggregation, which is still 88%. For example, when n consecutive carriers are aggregated, the transmission bandwidth of LTE-G 230MHz = 11*2*n = 22n KHz, and the spectrum utilization rate = 22n / 25n = 88%.

[0113] Since the guard interval between adjacent carriers is small, higher requirements are placed on the design of the filter. Specifically, in order to avoid interference between adjacent carriers, the roll-off when using the filter for filtering needs to be steeper. According to the requirements of the Ministry of Industry and Information Technology's Document No. 165 (2018), the output power of each carrier is 30dbm (decibel relative to onemilliwatt), the useless transmission power is -18dbm, and the bilateral power superposition of adjacent carriers increases by 3db, that is, the filtering steepness is -51dbm, which requires higher filtering performance of the filter, making the design of the filter more difficult.

[0114] Figure 7Schematic diagram of the distribution of subcarriers in the case of single carrier operation of IOT-G 230MHz in the prior art. Figure 7 Introduce IOT-G 230MHz.

[0115] The frame structure length of IOT-G 230MHz is 10ms, the carrier bandwidth is 25KHz, the subcarrier spacing is 3.75KHz in single carrier operation, 6 subcarriers are deployed in each carrier bandwidth, and the carrier bandwidth is 26.25KHz. In the case of multi-carrier aggregation, the protection interval between adjacent carriers is 1.25KHz. According to the calculation method of transmission bandwidth of 3GPP, the transmission bandwidth in single carrier operation = 3.75*6 = 22.5KHz, and the spectrum utilization rate = 22.5 / 25 = 90%.

[0116] Since the carrier bandwidth of IOT-G 230MHz is 26.25KHz, and the National Radio and Television Commission limits the working bandwidth of 25kHz in the 230MHz band, the filter forcibly clips the main lobe of the edge subcarrier, which will cause a large signal energy loss or distortion, affect the quality of the transmitted signal, and cause the system spectrum efficiency to decrease and the anti-interference ability to decrease. The IOT-G 230 system places the peak point in the passband and cuts off the entire main lobe outside the edge subcarrier. When there is phase noise or Doppler frequency shift, the edge subcarrier drifts beyond the passband range, which will cause the edge subcarrier signal to deteriorate and interfere with adjacent subcarriers.

[0117] Through the analysis of the discrete carrier flexible aggregation method proposed in the present invention, it can be seen that the carrier bandwidth in the present invention is 25KHz, the subcarrier spacing in the single carrier working condition is 2.5KHz, and 7 or 9 subcarriers are deployed in each carrier bandwidth. The transmission bandwidth in the single carrier working condition is 17.5KHz or 22.5KHz, and the spectrum utilization rate is 70% or 90%.

[0118] In the case of multi-carrier aggregation operation, the subcarrier spacing provided by the present invention is 2.5KHz, and the guard interval of adjacent carriers is 2.5KHz. Compared with the guard interval of 0.5KHz of the LTE-G 230MHz system, the guard interval of adjacent carriers is expanded by 5 times, the guard interval is wider, the interference between adjacent bands is smaller, and the filter design is simpler. According to the Nyquist theorem, the faster the frequency domain jitter drop, the longer the time domain tail, which causes the OFDM symbol tail to seriously produce inter-symbol interference. Compared with LTE-G 230MHz, the present invention slows down the speed reduction, reduces inter-symbol interference, and reduces EVM (Error Vector Magnitude).

[0119] In addition, in the case of multi-carrier aggregation, as the number of aggregated carriers increases, the spectrum utilization rate is significantly improved, the spectrum efficiency gradually approaches 100%, and the proportion of edge subcarriers affected by the filter gradually approaches 0%, and the overall performance of the received signal will gradually improve. Specifically, in the case of single-carrier operation, there are 7 or 9 subcarriers and 2 edge subcarriers; when 2 carriers are aggregated, there are 17 or 19 subcarriers, and the edge subcarriers are still 2, and the proportion of edge subcarriers gradually decreases.

[0120] Since the spectrum utilization rate of LTE-G 230MHz is always 88%, and the spectrum utilization rate in the technical solution provided by the present invention gradually increases with the number of aggregations. When a single carrier contains 7 subcarriers, the spectrum utilization rate of 3 carriers in continuous aggregation has exceeded that of the LTE-G 230MHz system; when a single carrier contains 9 subcarriers, the spectrum utilization rate of a single carrier has exceeded that of the LTE-G 230MHz system. In addition, in actual system applications, the wireless private network system also adopts a multi-carrier aggregation transmission solution, so the technical solution of the present invention is significantly better than the traditional LTE-G 230MHz wireless system.

[0121] The subcarrier spacing of the IOT-G 230MHz system under single-carrier operation is 3.75KHz, and the protection interval is 1.25KHz, while the protection interval of the adjacent carriers of the present invention is 2.5KHz. The design difficulty and filtering effect of the filter are significantly better than those of the IOT-G 230MHz system. In addition, since the protection interval of the adjacent carriers of the IOT-G 230MHz system is smaller than the subcarrier spacing, it cannot be reused. Under multi-carrier aggregation operation, the spectrum utilization rate is always 90%. When a single carrier contains 7 subcarriers, the spectrum utilization rate of 4 carriers in continuous aggregation operation has exceeded that of the LTE-G 230MHz system; when a single carrier contains 9 subcarriers, the spectrum utilization rate of the two carriers in aggregation operation has exceeded that of the LTE-G 230MHz system. At the same time, since the carrier bandwidth of the IOT-G 230MHz is greater than the working bandwidth limit of 25kHz, the filter forcibly clips the main lobe of the edge subcarrier, which will cause a large signal energy loss or distortion, affect the quality of the transmitted signal, and cause the system spectrum efficiency to decrease, and the anti-interference ability to decrease. Therefore, the technical solution of the present invention is obviously superior to the IOT-G 230MHz wireless system.

[0122] In order to compare the system performance under different subcarrier spacings, the effect of the filter on the received signal is designed and tested in the direct transmission scenario. Figure 8 As shown in the figure, it is a block diagram of the EVM test link in the direct transmission scenario. The specific test process is as follows: generate bits → digital modulation → resource mapping → OFEM modulation → shaping filtering → direct transmission → matched filtering → OFDM demodulation → resource demapping → test EVM.

[0123] The filter parameters for three different subcarrier spacings are shown in Table 2.

[0124] 2kHz 2.5kHz 3.75kHz Filter Type Equiripple FIR Lowpass Equiripple FIR Lowpass Equiripple FIR Lowpass Passband ripple depth 0.05dB 0.05dB 0.05dB Stopband Rejection 40dB 40dB 40dB Cutoff frequency 12.5k 12.5k 12.5k Passband frequency 12k 11.2k 12.1k

[0125] Table 2

[0126] According to the filter parameter design above, various performance indicators are tested for each subcarrier spacing under 256QAM. The received signal constellation diagrams corresponding to the three subcarriers are obtained. Among them, Fig. 9 This is the received signal constellation diagram of the LTE-G 230MHz system with a subcarrier spacing of 2KHz. Fig.10 The constellation diagram of the received signal of the technical solution of the present invention with a subcarrier spacing of 2.5KHz (a single carrier includes 7 subcarriers) is shown in FIG. Fig.11 The received signal constellation diagram of the IOT-G 230MHz system with a subcarrier spacing of 3.75KHz. Figure 9-11 In the figure, Scatter plot is a scatter plot, the horizontal axis In-phase is the value of the same phase, and the vertical axis Quadrature is the value of the orthogonal phase. Fig. 9 and Fig.11 , Fig.10 The received signal constellation diagram has higher clarity and higher judgment accuracy.

[0127] Table 3 shows the simulation results of three different subcarriers.

[0128] 2kHz 2.5kHz 3.75kHz Receive signal EVM 3.33 2.97 3.31 Out-of-band suppression 61dBc 61dBc 59dBc Filter length 593 149 353 Filter length / FFT 9.3 2.3 22.1

[0129] Table 3

[0130] It can be seen from Table 3 that the three subcarriers can meet the received signal EVM < 3.5% (the maximum EVM that a 256QAM signal can withstand), and the out-of-band suppression is greater than 48dBc; the LTE-G230MHz system with a subcarrier spacing of 2KHz and the IOT-G230MHz system with a subcarrier spacing of 3.75KHz, in order to achieve the current performance, the filter is too complex, and the filter length reaches 10 to 20 times the OFDM symbol length, which is difficult to achieve in practice. The technical solution provided by the present invention with a subcarrier spacing of 2.5KHz (a single carrier contains 7 subcarriers) has excellent performance in all aspects, and the length of the built-in filter is significantly reduced compared to the other two.

[0131] The following gives the value when the number of subcarriers in the carrier cluster is 10*N Subband When the modulation mode is 256QAM, the EVM result corresponding to the modulation mode is described as follows.

[0132] Since the EVM results corresponding to different modulation modes are not much different, only 256QAM is used as an example below. Table 4 shows the performance test results of flexible aggregation of different numbers of carriers in the technical solution provided by the present invention.

[0133]

[0134]

[0135] Table 4

[0136] It can be seen from Table 4 that as the number of continuous carriers increases, the EVM of the received signal gradually decreases. When the number of continuous carriers is greater than 5, the requirement of EVM < 1.5% can be achieved without discarding the edge subcarriers; the out-of-band suppression can meet the requirement of greater than 48dBc and stabilize between 63 and 65dBc; the spectrum utilization, also known as spectrum efficiency, increases with the increase in the number of continuous carriers. According to the above Table 1, it can be seen that the filter parameters designed by the present invention not only meet the wireless committee's out-of-band suppression requirements for 230MHz discrete carriers, ensuring the quality of signal transmission, but also the filtering performance is due to the EVM value meeting the requirements of high-order modulation (256QAM), and the traditional system can only achieve 64QAM, thereby limiting the improvement of data transmission capacity.

[0137] When the number of subcarriers in a carrier cluster is 10*N Subband -3, the performance test results of flexible aggregation with different numbers of carriers are similar to the above test results and will not be repeated here.

[0138] The discrete carrier flexible aggregation method provided by the present invention is aimed at a discrete narrowband wireless system with an operating frequency band of 223-235MHz and a carrier bandwidth of 25KHz. It adopts orthogonal frequency division multiplexing OFDM multi-carrier technology transmission, sets the subcarrier spacing to 2.5*nkHz, and n is 0.5, 1, 2 or 4. Under the condition of a single carrier 25KHz bandwidth restriction, the relative position invariant characteristic of 2.5*nkHz is utilized to make full use of the edge resources of a single carrier, and effectively improve the spectrum utilization rate. Compared with the LTE-G230MHz system and IOT-G230MHz system in the prior art, under the condition of continuous carrier aggregation, as the number of aggregated carriers increases, the spectrum utilization rate is significantly improved. In addition, the discrete carrier flexible aggregation scheme designed for discrete carrier characteristics and combined with waveform design, the key parameters of the filter are designed, and efficient filtering is achieved while meeting the requirements of the wireless radio transmission regulations, and the data transmission quality requirements of high-order modulation are met. In summary, the waveform design method for flexible aggregation of discrete carriers designed in the present invention for the 25KHz discrete narrowband characteristics of the 230MHz frequency band can effectively improve the utilization of spectrum resources, reduce the difficulty of filter design, and improve the system transmission capacity and quality when dedicated frequency band resources are limited.

[0139] Embodiment 2:

[0140] Based on the same inventive concept, the present invention also provides a communication system, the structural diagram of the communication system is as follows: Fig.12 As shown, the communication system includes: a transmitting end and a receiving end; the transmitting end is used to implement the discrete carrier flexible aggregation method of the above embodiment, and the receiving end is used to implement the discrete carrier flexible aggregation method of the above embodiment.

[0141] Embodiment 3:

[0142] Based on the same inventive concept, the present invention also provides a communication device, the structural diagram of the communication device is as follows: Fig.13 As shown, the communication device includes: a processing module and a communication module;

[0143] The processing module is applied to the transmitting end, in the communication device:

[0144] A processing module is used to determine that the subcarrier spacing in a discrete carrier is 2.5*nkHz, where n is 0.5, 1, 2 or 4; detect idle discrete carriers in discrete narrowband wireless system discrete carriers, and flexibly aggregate physically continuous idle discrete carriers to form a carrier cluster; divide the carrier cluster into multiple mutually orthogonal subcarriers according to the subcarrier spacing, and modulate the data to be sent to the subcarriers using OFDM multi-carrier technology; filter all carrier clusters separately based on a filter to obtain a filtered carrier cluster; the filter parameter of the filter is related to the number of idle discrete carriers in the carrier cluster;

[0145] The communication module is used to transmit the data to be sent modulated to the subcarrier through the filtered carrier cluster.

[0146] Optionally, the value range of the number of physically continuous idle discrete carriers included in the carrier cluster is [1, 159].

[0147] Optionally, when the subcarrier spacing in the discrete carrier is 2.5 kHz and the number of physically continuous idle discrete carriers in the carrier cluster is 1, the number of subcarriers in the carrier cluster is 7 or 9.

[0148] Optionally, when the subcarrier spacing in the discrete carrier is 2.5kHz and the number of physically continuous idle discrete carriers in the carrier cluster is greater than or equal to 1, the number of subcarriers in the carrier cluster is 10*N Subband -3 or 10*N Subband -1, N Subband is the number of physically continuous idle discrete carriers in the carrier cluster, 1≤N Subband ≤159.

[0149] Optional, when the number of subcarriers in the carrier cluster is 10*N Subband-3, the modulation mode of OFDM multi-carrier technology is 64QAM or 256QAM.

[0150] Optionally, when the number of subcarriers in the carrier cluster is 9, the modulation mode of the OFDM multi-carrier technology is QPSK, 16QAM or 64QAM.

[0151] Optional, when N Subband ≠1, and the number of subcarriers in the carrier cluster is 10*N Subband -1, the modulation mode of OFDM multi-carrier technology is 64QAM or 256QAM.

[0152] Optionally, the filter parameters of the filter include: sampling rate, cutoff frequency, passband frequency, passband ripple depth, stopband attenuation;

[0153] The filter parameter value of the filter is: sampling rate 2.5e3*N FFT , cut-off frequency 25e3*N Subband / 2, passband frequency 25e3*N Subband / 2-0.7e3, passband ripple depth 0.2dB, stopband attenuation 40dB, where N FFT is the number of Fourier sampling points, N Subband is the number of physically continuous idle discrete carriers in the carrier cluster.

[0154] Optionally, the discrete narrowband wireless system includes multiple carrier clusters, and the total number of idle discrete carriers included in the multiple carrier clusters is in the range of [1, 278];

[0155] The total number of subcarriers included in the multiple carrier clusters is 10*N′ Subband -3 or 10*N′ Subband -1, N′ Subband is the total number of idle discrete carriers contained in multiple carrier clusters, 1≤N′ Subband ≤278.

[0156] Embodiment 4:

[0157] Based on the same inventive concept, Fig.14 As shown, the present invention also provides an electronic device, which may be a computer device, a single-chip device, an intelligent mobile device, etc. The electronic device in this embodiment may include a processor, a memory, a transceiver component, etc. The memory, the processor, and the transceiver component are connected via a bus; the memory may be used to store an execution program, and an exemplary execution program may include instructions; the processor is used to execute the instructions stored in the memory. The memory may also be used to store data, which may be called and / or modified when the instructions are executed.

[0158] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in a readable storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of a discrete carrier flexible aggregation method in the above-mentioned embodiment.

[0159] Embodiment 5:

[0160] Based on the same inventive concept, the present invention also provides a readable storage medium, specifically an electronic device readable storage medium (Memory), which is a memory device in an electronic device for storing programs and data. It can be understood that the readable storage medium here can include both built-in storage media in electronic devices and extended storage media supported by electronic devices. The storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more execution programs (including program codes). It should be noted that the storage medium here can be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one disk memory. The processor can load and execute one or more instructions stored in the storage medium to implement the steps of a discrete carrier flexible aggregation method in the above embodiment.

[0161] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0162] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0163] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0164] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the application, but these changes, modifications or equivalent substitutions are all within the protection scope of the claims to be approved.

Claims

1. A method for flexible aggregation of discrete carriers, characterized in that: The method is applied to a discrete narrowband wireless system with an operating frequency band of 223-235 MHz and a carrier bandwidth of 25 KHz, and adopts orthogonal frequency division multiplexing OFDM multi-carrier technology for transmission, and comprises: Determine that the subcarrier spacing in the discrete carrier is 2.5*nkHz, where n is 0.5, 1, 2 or 4; Detecting idle discrete carriers in discrete carriers of the discrete narrowband wireless system, and flexibly aggregating physically continuous idle discrete carriers to form a carrier cluster; Dividing the carrier cluster into a plurality of mutually orthogonal subcarriers according to the subcarrier spacing, and modulating the data to be transmitted onto the subcarriers using OFDM multicarrier technology; All the carrier clusters are individually filtered based on a filter to obtain a filtered carrier cluster; a filtering parameter of the filter is related to the number of idle discrete carriers in the carrier cluster; The data to be sent modulated to the subcarrier is transmitted through the filtered carrier cluster.

2. The method according to claim 1, characterized in that The value range of the number of physically continuous idle discrete carriers included in the carrier cluster is [1, 159].

3. The method according to claim 2, characterized in that When the subcarrier spacing in the discrete carrier is 2.5 kHz and the number of physically continuous idle discrete carriers in the carrier cluster is 1, the number of subcarriers in the carrier cluster is 7 or 9.

4. The method according to claim 2, characterized in that: When the subcarrier spacing in the discrete carrier is 2.5 kHz and the number of physically continuous idle discrete carriers in the carrier cluster is greater than or equal to 1, the number of subcarriers in the carrier cluster is 10*N Subband -3 or 10*N Subband -1, N Subband is the number of physically continuous idle discrete carriers in the carrier cluster, 1≤N Subband ≤159.

5. The method according to claim 4, characterized in that When the number of subcarriers in the carrier cluster is 10*N Subband -3, the modulation mode of the OFDM multi-carrier technology is 64QAM or 256QAM.

6. The method according to claim 4, characterized in that When the number of subcarriers in the carrier cluster is 9, the modulation mode of the OFDM multi-carrier technology is QPSK, 16QAM or 64QAM.

7. The method according to claim 4, characterized in that When N Subband ≠1, and the number of subcarriers in the carrier cluster is 10*N Subband -1, the modulation mode of the OFDM multi-carrier technology is 64QAM or 256QAM.

8. The method according to any one of claims 1 to 7, characterized in that: The filter parameters of the filter include: sampling rate, cutoff frequency, passband frequency, passband ripple depth, and stopband attenuation; The filter parameter value of the filter is: sampling rate 2.5e3*N FFT , cut-off frequency 25e3*N Subband / 2, passband frequency 25e3*N Subband / 2-0.7e3, passband ripple depth 0.2dB, stopband attenuation 40dB, where N FFT is the number of Fourier sampling points, N Subband is the number of physically continuous idle discrete carriers in the carrier cluster.

9. The method according to claim 1, characterized in that: The discrete narrowband wireless system includes multiple carrier clusters, and the total number of idle discrete carriers included in the multiple carrier clusters is in the range of [1, 278]; The total number of subcarriers included in the multiple carrier clusters is 10*N′ Subband -3 or 10*N′ Subband -1, N′ Subband is the total number of idle discrete carriers contained in multiple carrier clusters, 1≤N′ Subband ≤278.

10. A communication device, characterized in that: include: A processing module, used for determining that the subcarrier spacing in the discrete carrier is 2.5*nkHz, where n is 0.5, 1, 2 or 4; Detecting idle discrete carriers in the discrete narrowband wireless system discrete carriers, flexibly aggregating physically continuous idle discrete carriers to form a carrier cluster; dividing the carrier cluster into a plurality of mutually orthogonal subcarriers according to the subcarrier interval, and modulating the data to be sent to the subcarriers using OFDM multicarrier technology; performing separate filtering on all the carrier clusters based on a filter to obtain a filtered carrier cluster; the filtering parameter of the filter is related to the number of idle discrete carriers in the carrier cluster; A communication module, configured to transmit the data to be sent modulated to the subcarrier through the filtered carrier cluster; The communication device is applied to a discrete narrowband wireless system with an operating frequency band of 223-235 MHz and a carrier bandwidth of 25 KHz, and adopts orthogonal frequency division multiplexing OFDM multi-carrier technology for transmission.

11. A method for flexible aggregation of discrete carriers, characterized in that: The method is applied to a discrete narrowband wireless system with an operating frequency band of 223-235 MHz and a carrier bandwidth of 25 KHz, and adopts orthogonal frequency division multiplexing OFDM multi-carrier technology for transmission, and comprises: receiving data to be received; Performing matched filtering and OFDM demodulation processing on the data to be received to obtain processed data; The data to be received is to determine that the subcarrier spacing in the discrete carrier is 2.5*nkHz, where n is 0.5, 1, 2 or 4; detect the idle discrete carriers in the discrete carriers of the discrete narrowband wireless system, and flexibly aggregate the physically continuous idle discrete carriers to form a carrier cluster; divide the carrier cluster into multiple mutually orthogonal subcarriers according to the subcarrier spacing, and use OFDM multi-carrier technology to modulate the data to be sent to the subcarriers; based on the filter, all the carrier clusters are individually filtered to obtain the filtered carrier cluster; the filtering parameters of the filter are related to the number of idle discrete carriers in the carrier cluster; and the data is obtained after being modulated to the subcarrier through the filtered carrier cluster.

12. A communication device, characterized in that: include: A communication module, used for acquiring received data; A processing module is used to perform matched filtering and OFDM demodulation processing on the data to be received to obtain processed data; the data to be received is to determine that the subcarrier spacing in the discrete carrier is 2.5*n kHz, and n is 0.5, 1, 2 or 4; detect idle discrete carriers in discrete carriers of a discrete narrowband wireless system, and flexibly aggregate the physically continuous idle discrete carriers to form a carrier cluster; divide the carrier cluster into multiple mutually orthogonal subcarriers according to the subcarrier spacing, and use OFDM multi-carrier technology to modulate the data to be sent to the subcarriers; based on a filter, all the carrier clusters are individually filtered to obtain a filtered carrier cluster; the filtering parameters of the filter are related to the number of idle discrete carriers in the carrier cluster; and the data is obtained after being modulated to the subcarrier through the filtered carrier cluster.

13. A communication system, characterized in that: It comprises a transmitting end and a receiving end; the transmitting end is used to implement the discrete carrier flexible aggregation method described in any one of claims 1 to 9 above, and the receiving end is used to implement the discrete carrier flexible aggregation method described in claim 11 above.

14. An electronic device, characterized in that: include: at least one processor and memory; The memory and the processor are connected via a bus; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, the discrete carrier flexible aggregation method as described in any one of claims 1 to 9 above, or the discrete carrier flexible aggregation method as described in claim 11 above is implemented.

15. A readable storage medium, characterized in that: An execution program is stored thereon to implement the discrete carrier flexible aggregation method as described in any one of claims 1 to 9 above, or to implement the discrete carrier flexible aggregation method as described in claim 11 above.

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