CN114513817A

CN114513817A - Frequency selection method based on medium-long wave communication, terminal equipment and storage medium

Info

Publication number: CN114513817A
Application number: CN202210292997.7A
Authority: CN
Inventors: 刘刚; 龙剑飞; 王国波
Original assignee: Guangzhou Haige Communication Group Inc Co
Current assignee: Guangzhou Haige Communication Group Inc Co
Priority date: 2022-03-23
Filing date: 2022-03-23
Publication date: 2022-05-17

Abstract

The embodiment of the application discloses a frequency selection method based on medium-long wave communication, terminal equipment and a storage medium, which are used for improving demodulation sensitivity by reducing message transmission rate so as to select a desired frequency point. The method in the embodiment of the application comprises the following steps: receiving radio frequency signals corresponding to a first frequency point which are sent at least twice through a first preset number of channels; screening out a second preset number of radio frequency signals from the first preset number of radio frequency signals, wherein the second preset number is smaller than the first preset number; feeding back an Acknowledgement (ACK) signal; and receiving the service data sent according to the ACK signal.

Description

Frequency selection method based on medium-long wave communication, terminal equipment and storage medium

Technical Field

The present application relates to the field of communications, and in particular, to a frequency selection method, a terminal device, and a storage medium based on medium-long wave communications.

Background

In actual application of the prior art, due to the adoption of a few agreed frequency points, although the scanning time is shortened, better frequency points can be missed, and even frequency points selected by experience cannot be used for establishing link communication, so that the communication effect cannot be guaranteed. The selection of the experience frequency point depends on factors such as geographical position, personal use experience and the like, and the experience frequency point can be established only by arranging stations in advance for searching, so that the experience frequency point cannot adapt to the environment with instantaneous change.

Disclosure of Invention

The embodiment of the application provides a frequency selection method based on medium-long wave communication, terminal equipment and a storage medium, which are used for improving demodulation sensitivity by reducing message transmission rate so as to select a desired frequency point.

A first aspect of the present application provides a frequency selection method based on medium-long wave communication, which may include:

receiving radio frequency signals corresponding to a first frequency point which are sent at least twice through a first preset number of channels;

screening out a second preset number of radio frequency signals from the first preset number of radio frequency signals, wherein the second preset number is smaller than the first preset number;

feeding back an Acknowledgement (ACK) signal;

and receiving the service data sent according to the ACK signal.

A second aspect of the present application provides a frequency selection method based on medium-long wave communication, which may include:

sending radio frequency signals corresponding to a first frequency point at least twice, wherein the radio frequency signals corresponding to the first frequency point are used for screening the radio frequency signals;

receiving an Acknowledgement (ACK) signal;

and sending service data according to the ACK signal.

A third aspect of the present application provides a terminal device, which may include:

the receiving and transmitting module is used for receiving radio frequency signals corresponding to the first frequency point which are transmitted at least twice through a first preset number of channels;

the processing module is used for screening out a second preset number of radio frequency signals from the first preset number of radio frequency signals, wherein the second preset number is smaller than the first preset number;

the transceiver module is further configured to feed back an acknowledgement ACK signal; and receiving the service data sent according to the ACK signal.

A fourth aspect of the present application provides a terminal device, which may include:

the receiving and sending module is used for sending radio frequency signals corresponding to a first frequency point at least twice, and the radio frequency signals corresponding to the first frequency point are used for screening the radio frequency signals; receiving an Acknowledgement (ACK) signal; and sending service data according to the ACK signal.

A fifth aspect of the present application provides a terminal device, which may include:

a memory storing executable program code;

a processor and transceiver coupled with the memory;

the processor calls the executable program code stored in the memory, so that the processor and the transceiver respectively correspondingly execute the method according to the first aspect or the second aspect of the application.

Yet another aspect of embodiments of the present application provides a computer-readable storage medium comprising instructions that, when executed on a processor, cause the processor to perform the method of the first or second aspect of the present application.

In yet another aspect, an embodiment of the present invention discloses a computer program product, which when run on a computer, causes the computer to execute the method of the first aspect or the second aspect of the present application.

In another aspect, an embodiment of the present invention discloses an application publishing platform, configured to publish a computer program product, where when the computer program product runs on a computer, the computer is caused to execute the method according to the first aspect or the second aspect of the present application.

According to the technical scheme, the embodiment of the application has the following advantages:

in the embodiment of the application, the main terminal equipment sends the radio frequency signals corresponding to the first frequency point at least twice, wherein the radio frequency signals corresponding to the first frequency point are used for screening the radio frequency signals; receiving radio frequency signals corresponding to a first frequency point, which are sent at least twice, from the terminal equipment through a first preset number of channels; screening out a second preset number of radio frequency signals from the first preset number of radio frequency signals by the slave terminal equipment, wherein the second preset number is smaller than the first preset number; feeding back an Acknowledgement (ACK) signal from the terminal equipment; the main terminal equipment receives an ACK signal; the main terminal equipment sends service data according to the ACK signal; and receiving the service data sent according to the ACK signal from the terminal equipment. The demodulation sensitivity is improved by reducing the message transmission rate, so that the desired frequency point is selected.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the embodiments and the drawings used in the description of the prior art, and obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained according to the drawings.

Fig. 1 is a schematic diagram of a master terminal device sending frequency points and all frequency points of a slave terminal device circularly scanning and waiting in the prior art;

FIG. 2 is a schematic diagram illustrating an embodiment of a frequency selection method based on medium-long wave communication in an embodiment of the present application;

FIG. 3A is a diagram illustrating an embodiment of a full-band real-time watch scan;

fig. 3B is a schematic diagram of a basic link flow between a master terminal device and a slave terminal device in the embodiment of the present application;

fig. 4 is a schematic diagram of another embodiment of a frequency selection method based on long-medium wave communication in the embodiment of the present application;

FIG. 5A is a schematic diagram of a software pass-through connection of two FPGAs according to an embodiment of the present application;

FIG. 5B is a schematic diagram of two pieces of FPGA connected to DAC in the embodiment of the present application;

FIG. 5C is a basic flow chart of the present embodiment for processing the received RF signal;

fig. 5D is a schematic diagram of a sampling algorithm employed by the terminal device in the embodiment of the present application;

fig. 5E is a schematic diagram of an interface connection between a channel board, a service board and a main control board included in the terminal device in the embodiment of the present application;

FIG. 5F is a schematic diagram of two FPGAs connected to an ADC and a DAC according to an embodiment of the present application;

fig. 5G is a schematic diagram of a hardware connection in the terminal device in the embodiment of the present application;

fig. 5H is a schematic diagram of connection of each interface of hardware in the terminal device in the embodiment of the present application;

FIG. 6 is a schematic diagram of an embodiment of a terminal device in the embodiment of the present application;

fig. 7 is a schematic diagram of another embodiment of the terminal device in the embodiment of the present application;

fig. 8 is a schematic diagram of another embodiment of the terminal device in the embodiment of the present application.

Detailed Description

For a person skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. The embodiments in the present application shall fall within the protection scope of the present application.

The traditional communication link establishment mode of medium-long wave communication is that the main terminal device fixes single frequency point transmission and the slave terminal device scans and waits. Because the waveform itself is long (the order of 200 seconds is needed for signaling of 12.5 bytes/minute), the master terminal device needs to send for a long time to ensure that the receiving frequency point of the slave terminal device is matched with the transmitting frequency point of the master terminal device, so that the high-power master terminal device faces a very serious test and is also easily detected by an enemy according to continuous power. Fig. 1 is a schematic diagram of a prior art in which a master terminal device sends frequency points and all frequency points of a slave terminal device are cyclically scanned and waited.

In view of the above practical situations, in practical application of the prior art, an agreed few frequency points are often used, and although the scanning time is shortened by using the method, better frequency points may be missed, and even the frequency points selected by experience cannot be used for establishing link communication, so that the communication effect cannot be guaranteed. The selection of the experience frequency point depends on factors such as geographical position, personal use experience and the like, and the experience frequency point can be established only by arranging stations in advance for searching, so that the experience frequency point cannot adapt to the environment with instantaneous change.

According to the use requirements of the medium-long wave communication system, the intelligent frequency selection technology of the medium-long wave terminal equipment is provided by combining the existing powerful signal processing technology, so that a more reliable and efficient communication scheme is realized. In the embodiment of the application, the demodulation sensitivity is improved by reducing the message transmission rate. The technology is mainly used for weak signal demodulation, so that the frequency selection time is longer due to the limitation of frequency and message types; although the message transmission time is long, extremely weak signals can be stably and reliably received, and even signals which are lower than noise, for example, about 30dB can be received.

The following further describes the technical solution of the present application by way of an embodiment, as shown in fig. 2, which is a schematic diagram of an embodiment of a frequency selection method based on medium-long wave communication in the embodiment of the present application, and the method may include:

201. and sending the radio frequency signals corresponding to the first frequency point at least twice, wherein the radio frequency signals corresponding to the first frequency point are used for screening the radio frequency signals.

And receiving radio frequency signals of a first preset number corresponding to the first frequency point, which are sent at least twice, through a first preset number of channels.

The first terminal device, that is, the master terminal device, sends the radio frequency signals corresponding to the first frequency points at least two times, and the second terminal device, that is, the slave terminal device, receives the radio frequency signals corresponding to the first frequency points at least two times through the first preset number of channels.

Optionally, the first frequency point is selected by the main terminal device according to experience data.

Optionally, the empirical data includes at least one of historical spectral data, empirically available frequency bands, and geographic location. Optionally, the empirical data may also include other information.

Illustratively, the frequency of the medium-long wave is 200KHz to 400KHz (66.6 frequency points are scanned in total), for the convenience of calculation, 64 frequency points are usually used for calculation, and 66 paths can be expanded under the condition of abundant resources. According to the method, a plurality of Programmable Gate arrays (FPGAs) are used for parallel computation, a full-band channel is waited in parallel, a master terminal device needs to continuously send radio frequency signals twice or more, and a slave terminal device can receive the radio frequency signals.

202. And screening out a second preset number of radio frequency signals from the first preset number of radio frequency signals, wherein the second preset number is smaller than the first preset number.

Illustratively, after comprehensive evaluation, some channels are excluded through conditions such as empirical information and current spectrum monitoring information, and information such as 24 channels, 20 channels, 16 channels and the like is screened out, so that full-band scanning is realized. Fig. 3A is a schematic diagram of a full-band real-time waiting scan according to an embodiment of the present invention.

203. And feeding back an Acknowledgement (ACK) signal.

An acknowledgement ACK signal is received.

And the slave terminal equipment feeds back the ACK signal to the master terminal equipment, and the master terminal equipment receives the ACK signal.

204. And sending service data according to the ACK signal.

And receiving the service data sent according to the ACK signal.

The master terminal device may send the service data according to the received ACK signal, and the slave terminal device receives the service data sent by the master terminal device.

Exemplarily, as shown in fig. 3B, a basic link flow diagram between a master terminal device and a slave terminal device in the embodiment of the present application is shown. The basic working flow is as follows: the master terminal device sends the selected 1 frequency point (or 12.5byte/min) according to 50byte/min (1 is selected for 24 frequency points) → slave terminal device receiving → slave terminal device sending Acknowledgement (ACK) → master terminal device receiving ACK (speed is adjusted according to signal-to-noise ratio (SNR)).

As shown in fig. 4, for another exemplary illustration of a frequency selection method based on medium-long wave communication in the embodiment of the present application, the method may include:

401. and sending the radio frequency signals corresponding to the first frequency point at least twice, wherein the radio frequency signals corresponding to the first frequency point are used for screening the radio frequency signals.

402. And screening out a second preset number of radio frequency signals from the first preset number of radio frequency signals, wherein the second preset number is smaller than the first preset number.

Optionally, the method is applied to a terminal device, where the terminal device includes a channel board and a service board, the service board includes a first FPGA and a second FPGA, one end of the first FPGA is connected to an analog-to-digital converter ADC, the other end of the first FPGA is connected to a digital-to-analog converter DAC, a pin of the second FPGA is set to a high resistance, and input and output pins of the first FPGA and the second FPGA are consistent;

the screening out a second preset number of radio frequency signals from the first preset number of radio frequency signals may include: processing the radio frequency signals of the first preset number by using the first analog-to-digital converter (ADC) through the channel board to obtain intermediate frequency signals of the first preset number; the intermediate frequency signals of the first preset number are transmitted to the second FPGA through the first FPGA; and screening out a second preset number of intermediate frequency signals from the first preset number of intermediate frequency signals through the first FPGA and the second FPGA.

It can be understood that, since the preselected frequency points cannot be uniformly distributed on the two FPGAs, the master control continuous task needs to be uniformly distributed on the two FPGAs, and meanwhile, in order to reduce the transmission complexity of the interface, the two FPGAs simultaneously implement the functions of full-band channel down-conversion and the like, and the radio frequency signal is directly transmitted from the chip FPGA1 to the chip FPGA2 through an Analog-to-Digital Converter (ADC), and the consistency of the FPGA program can be ensured through the following scheme. The input pins and the output pins of the two FPGAs are required to be completely consistent. Fig. 5A is a schematic diagram of a software through connection two FPGAs in the embodiment of the present application.

Because the two FPGAs are used, only one path of Digital-to-Analog Converter (DAC) sending end is needed, and the high resistance can be set through the corresponding DAC pins in order to guarantee the consistency of the FPGA program loading files. And the same General Purpose Input/Output (GPIO) pin can be pulled high and low to be used as the Identification (ID) of the device, thereby facilitating the subsequent debugging and protocol simplification. Fig. 5B is a schematic diagram of two pieces of FPGA connecting DAC in the embodiment of the present application.

It should be noted that the FPGA in the present application relates to a chip of zynq. Replaces the FPGA and the DSP in the prior art.

At present, the domestic main application scheme is 7K325T + DSP (TI 6416). The technical scheme of the application is as follows: various waveforms on the zynq7045 short wave are processed by replacing Digital Signal Processing (DSP) with PS, and the requirements can be met on the computing power.

zynq: the ZYNQ series chip of saint corporation is the first extensible processing platform in the industry by saint corporation (Xilinx) and is intended to provide the required processing and computing performance levels for high-end embedded applications such as video surveillance, automobile driver assistance, and factory automation.

403. Equally dividing the second preset number of intermediate frequency signals through the first FPGA and the second FPGA, and performing signal detection by using Fast Fourier Transform (FFT) to obtain a signal detection result.

It can be understood that, from the terminal device, the channel board transmits to the service board the intermediate frequency signal, the bandwidth of the intermediate frequency signal can be set to 200KHz, and the broadband reception of the medium-long wave is realized. And the down-conversion and down-sampling of the full-frequency-band channel are realized through broadband receiving and multi-channel processing. Basic signal processing flow: rf signal → channel board → ADC → if signal → multi-channel down-conversion (mixing + Direct Data Control (DDC)).

Fig. 5C is a basic flowchart of the processing of the received rf signal according to the embodiment of the present application. A basic flow of processing the received rf signal from the terminal device is described as follows:

1. dividing the radio frequency signal into two paths through an ADC (analog-to-digital converter), and simultaneously delivering the two paths to two FPGAs (field programmable gate arrays);

2. the two sides simultaneously carry out 64 paths of down-conversion processing (although some meaningless repeated resources are consumed, the workload of interface development is reduced);

3. by actually measuring frequency spectrums, historical experiences and the like, for example, frequency points of 24 paths before ranking are screened out, and 12 paths are equally divided for two pieces of FPGA;

4. if the empirical data and the frequency spectrum are too poor, less than 12 paths are selected better, and the probability of subsequent false alarm detection (which depends on actual measurement experience accumulation) is reduced;

5. the FPGA performs Fast Fourier Transform (FFT) spectrum sensing and signal detection, and sends the signal detection result to a Processing System (PS) side.

A Central Processing Unit (CPU) continuously configures a signal detection result at the PS side; the PS side can report the decoding signal to the CPU; the FFT data is relayed to the CPU by the PS.

In fig. 5C, MIX: a mixer.

And (3) PS side decoding: PS (Processing System), which is a part of System On Chip (SOC) of ARM (advanced RISC machines) independent of FPGA, decoding at PS side, i.e. decoding process is completed in ARM.

It can be understood that the terminal device further includes a main control board, and the main control board includes a CPU.

404. And selecting a target channel according to the signal detection result.

Optionally, the target channel is an optimal channel.

405. And changing the center frequency of the channel board to correspond to the target channel.

406. And feeding back an Acknowledgement (ACK) signal.

407. And sending service data according to the ACK signal.

And receiving the service data sent according to the ACK signal.

Optionally, the receiving the service data sent according to the ACK signal may include: and receiving the service data sent according to the ACK signal through the target channel.

Optionally, the receiving, by the slave terminal device, the radio frequency signal corresponding to the first frequency point sent at least twice through the first preset number of channels may include: the slave terminal equipment receives radio frequency signals corresponding to the first frequency point sent at least twice through a first preset number of channels by adopting a 4-time oversampling algorithm;

the receiving, from the terminal device, the service data transmitted according to the ACK signal may include: and the slave terminal equipment receives the service data sent according to the ACK signal by adopting an 8-time oversampling algorithm.

It can be understood that, when the service frequency selection and the link establishment are carried out, in order to ensure more parallel channel detection, the algorithm of 4 times oversampling is adopted to guarantee. After frequency selection determination, the channel is assigned to single-pass down-conversion to realize signal detection by using 8 times of over-sampled baseband data. At this time, the center frequency of the channel board also needs to be changed to adapt to the narrow-band filtering of the analog part under the single channel on the channel board. Fig. 5D is a schematic diagram of a sampling algorithm adopted by the terminal device in this embodiment.

PL side: programmable Logic (progarmble Logic), which is part of the FPGA.

Optionally, the terminal device includes a channel board, a service board, and a main control board; the channel board, the service board and the main control board are connected through serial ports.

Fig. 5E is a schematic diagram of an interface connection between a channel board, a service board and a main control board included in the terminal device in this embodiment. An interface connection diagram based on core devices such as the FPGA and the zynq is shown as 5E.

Optionally, the second preset number of channel frequencies is 50 bytes/min or 11 bytes/min.

It is understood that, the slave terminal device scans with 50 bytes/min, for example, the slave terminal device waits for 12 (50 bytes/min) frequencies in real time (may also be configured to use 11 bytes/min to scan all frequencies), and this rate selection may be selected according to the actual experimental effect, and is not limited specifically here.

The range can be greatly reduced after the corresponding frequency is eliminated based on the local position and the like, and the detection can be changed into 8 paths of FGPA processing, so that the method is more practical. (considering the scheme demonstration, the more the parallel detection effect paths are, the better) in order to improve the throughput, the frequency is preferably changed, and the medium-long wave does not use the shift rate of 12.5 bytes/min (which can be configured according to the test requirement).

Fig. 5F is a schematic diagram of two FPGAs connected to an ADC and a DAC according to the embodiment of the present application. Because the signal detection resource is the most key in the invention, each FPGA can only process 12 paths of signal detection, and if the frequency band is divided into an upper half and a lower half, the data which needs to be detected can not be guaranteed to be evenly distributed on the two FPGAs. The interface transfers IQ data of the corresponding channel, which increases the debugging workload. Therefore, full-band channel filtering is achieved through the two groups of the two FPGAs, detection tasks of the two FPGAs are distributed comprehensively through the main control, and the purpose of detecting load balance is achieved. The hardware ADC needs to be identically connected to two pieces of FPGA. However, the transmitting DAC only needs to be connected with one FPGA.

Wherein, IQ data: the data of the IQ signal is obtained by IQ modulating the signal, and essentially, the IQ signal modulates the amplitude of orthogonal carrier Cos and Sin components by using a pair of I and Q signals, and the I and Q signals are added to each other, so that arbitrary modulation on the amplitude and phase can be expressed.

A brief comparison (convenient expansion, reserved debug margin) is made between the chip Z7045 and the chip Z7100 resources as shown in table 1:

TABLE 1

The Z7100 logical resource is 1.26 times that of Z7045, and the Z7100 storage resource is 1.38 times that of Z7045. The Z7100 can be expanded moderately under the condition that Z7045 resources are in shortage, but if a multiple of calculation amount is needed, devices must be added (the Z7100 and the Z7045 Pin-to-Pin are compatible and are replaced by a 2HF integrated body).

BRAM: block RAM, Block Random Access Memory. After the BRAM is programmed and configured, the memory function can be realized. The BRAMs are arranged in the FPGA in an array mode, are the main parts of the FPGA for realizing various storage functions and are the true synchronous RAMs of the double read/write ports.

Fig. 5G is a schematic diagram of hardware connection in the terminal device in the embodiment of the present application. Fig. 5H is a schematic diagram of connection of each interface of hardware in the terminal device in this embodiment.

1. The channel board provides a clock signal (guarantee amplitude) through a 4-by-4 interface;

2. black bold lines indicate 16bit Low Voltage Differential Signaling (LVDS);

the ADC is transmitted from 7045-A to 7045-B, the code of 7045-B is the same as that of 7045-A, and the hardware of an output pin is suspended.

3. 7010 the service board interacts with 16-bit LVDS signals, hardware is pulled high and pulled low through a pin to serve as an ID number of the FPGA, and code uniformity can be kept;

4. the new board wants to add, the channel board AGC feeds some information back to the service board (GPIO of dotted line).

The following is a brief description of the interfaces between the main control board, the service board and the channel board in the terminal device, as follows:

(1) master control board → service board (interface type list)

The information that the Tx terminal needs to send is sent to the PS side of the service board by the main control board;

the Cfg master control board needs to configure the mapping relation of the detection channel at the PL side of the service board and can close the switch;

the Cfg master control board configures a service board working mode, mainly mapping a detection module to an 8-time sampling point detection module.

(2) Master control board ← service board

The service board reports the local noise to the PS side of the main control board;

the demodulation information of the Rx service board is reported to the main control PS through the PS;

the service board reports information such as PTT and the like to the main control board. The PTT button is a button for controlling transmission, and the transmitter is switched from waiting to transmitting when there is a signal (generally, on-ground).

(3) Main control board and channel board (need service board transfer)

The main control board controls the channel board to be switched to a narrow-band filtering mode (designed to be switched to frequency) pure broadband mode without switching, and the set successful self-Error correction (ARQ) needs to be fed back to the main control board.

It can be understood that, in the following, by way of example, a resource statistic is made for the technical solution of the present application.

As shown in table 2, the resource statistics is performed by using 8-fold oversampling algorithm for single-path resources.

	slice	DSP	BRAM(36Kb)
				General of	21000-6000	180	277-73
11byte/min detection	1600	22	43
				50byte/min detection	1600	22	43
180byte/min detection	1600	22	20
				360byte/min detection	1600	22	11
720byte/min detection	1600	22	11
				DUC	1000	32	9
DDC	3000	34	22

TABLE 2

Description of the drawings: in the lowest two detection resources, the RAM for caching data is 36.5 (the table has debugging resource occupation). The sampling rate is reduced by one time and the RAM used is estimated in 19.

It can be understood that, in the estimation of the multipath parallel computing resource, in order to improve the utilization efficiency of the device, the original detection scheme of 8 times oversampling can be changed into 4 times oversampling (performance is expected to have a loss of 0.5dB, for example), and the performance has little influence on the pull-distance test for the use scenario of the whole waveform system.

Optionally, the FPGA operation master clock is 157.2864 MHz.

The 9.6K symbols used for the multiplexing are 8192 clk symbols between each symbol. The number of paths that can be reused for each set of detection resources is 8192/1024 (FFT length used by the algorithm) ═ 8 paths. If all the resources are tested with 12.5 bytes/min, 8 × 8-64 resources can be reused. There is no extra cost for the logic resources and what needs to be solved is the storage problem.

In the embodiment of the application, the main terminal equipment sends radio frequency signals corresponding to a first frequency point at least twice, wherein the radio frequency signals corresponding to the first frequency point are used for screening the radio frequency signals; screening out a second preset number of radio frequency signals from the first preset number of radio frequency signals by the slave terminal equipment, wherein the second preset number is smaller than the first preset number; the slave terminal equipment equally divides the second preset number of intermediate frequency signals through the first FPGA and the second FPGA, and performs signal detection by using Fast Fourier Transform (FFT) to obtain a signal detection result; selecting a target channel from the terminal equipment according to the signal detection result; changing the center frequency of the channel board from the terminal equipment to correspond to the target channel; feeding back an Acknowledgement (ACK) signal from the terminal equipment; and the main terminal equipment sends service data according to the ACK signal. That is, in the present application, the target channel may be selected from the terminal device with reference to empirical data, for example, with reference to an empirical frequency. The frequency selection is more accurate, and compared with the prior art in the same wave band, the frequency selection efficiency is higher and faster. Because the medium-long wave mainly passes through ground wave communication, the frequency selection characteristics of the medium-long wave are influenced by various factors such as different weather, seasons, morning and evening, surrounding environment and the like due to the special communication property of the medium-long wave. The scheme can effectively overcome the working frequency band characteristic and accurately and quickly select the optimal frequency point.

As shown in fig. 6, which is a schematic diagram of an embodiment of a terminal device in the embodiment of the present application, the method may include:

the transceiver module 601 is configured to receive radio frequency signals corresponding to a first frequency point, which are sent at least twice, through a first preset number of channels;

a processing module 602, configured to screen out a second preset number of radio frequency signals from the first preset number of radio frequency signals, where the second preset number is smaller than the first preset number;

the transceiver module 601 is further configured to feed back an acknowledgement ACK signal; and receiving the service data sent according to the ACK signal.

Optionally, the terminal device includes a channel board and a service board, where the service board includes a first FPGA and a second FPGA, one end of the first FPGA is connected to the ADC, and the other end of the first FPGA is connected to the DAC, a pin of the second FPGA is set to a high resistance, and input and output pins of the first FPGA and the second FPGA are identical;

a processing module 602, configured to specifically process, through the channel board, the radio frequency signals of the first preset number by using the first analog-to-digital converter ADC, so as to obtain intermediate frequency signals of the first preset number; the intermediate frequency signals of the first preset number are transmitted to the second FPGA through the first FPGA; and screening out a second preset number of intermediate frequency signals from the first preset number of intermediate frequency signals through the first FPGA and the second FPGA.

Optionally, the processing module 602 is further configured to equally divide the second preset number of intermediate frequency signals by using the first FPGA and the second FPGA, and perform signal detection by using a fast fourier transform FFT to obtain a signal detection result; selecting a target channel according to the signal detection result; changing the center frequency of the channel board to correspond to the target channel;

the transceiver module 601 is specifically configured to receive, through the target channel, the service data sent according to the ACK signal.

Optionally, the transceiver module 601 is specifically configured to receive, through a first preset number of channels, radio frequency signals corresponding to a first frequency point sent at least twice by using a 4-fold oversampling algorithm;

the transceiver module 601 is specifically configured to receive the service data sent according to the ACK signal by using an 8-fold oversampling algorithm.

Optionally, the terminal device includes a channel board, a service board, and a main control board;

the channel board, the service board and the main control board are connected through serial ports.

As shown in fig. 7, which is a schematic diagram of another embodiment of the terminal device in the embodiment of the present application, the method may include:

the transceiver module 701 is configured to send radio frequency signals corresponding to a first frequency point at least twice, where the radio frequency signals corresponding to the first frequency point are used to screen radio frequency signals; receiving an Acknowledgement (ACK) signal; and sending service data according to the ACK signal.

Optionally, the first frequency point is selected according to empirical data, where the empirical data includes at least one of historical spectrum data, an empirical available frequency band, and a geographic location.

As shown in fig. 8, which is a schematic diagram of another embodiment of the terminal device in the embodiment of the present application, the method may include:

fig. 8 is a block diagram illustrating a partial structure of a mobile phone related to a terminal device provided in an embodiment of the present invention. Referring to fig. 8, the handset includes: radio Frequency (RF) circuitry 810, memory 820, input unit 830, display unit 840, sensor 850, audio circuitry 860, wireless fidelity (Wi-Fi) module 870, processor 880, and power supply 890. Those skilled in the art will appreciate that the handset configuration shown in fig. 8 is not intended to be limiting and may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components.

The following describes each component of the mobile phone in detail with reference to fig. 8:

the RF circuit 810 may be used for receiving and transmitting signals during information transmission and reception or during a call, and in particular, for processing downlink information of a base station after receiving the downlink information to the processor 880; in addition, the data for designing uplink is transmitted to the base station. In general, RF circuit 810 includes, but is not limited to, an antenna, at least one Amplifier, a transceiver, a coupler, a Low Noise Amplifier (LNA), a duplexer, and the like. In addition, the RF circuit 810 may also communicate with networks and other devices via wireless communication. The wireless communication may use any communication standard or protocol, including but not limited to Global System for Mobile communication (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), email, Short Messaging Service (SMS), and the like.

The memory 820 may be used to store software programs and modules, and the processor 880 executes various functional applications and data processing of the cellular phone by operating the software programs and modules stored in the memory 820. The memory 820 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, a phonebook, etc.) created according to the use of the cellular phone, and the like. Further, the memory 820 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.

The input unit 830 may be used to receive input numeric or character information and generate key signal inputs related to user settings and function control of the cellular phone. Specifically, the input unit 830 may include a touch panel 831 and other input devices 832. The touch panel 831, also referred to as a touch screen, can collect touch operations performed by a user on or near the touch panel 831 (e.g., operations performed by the user on the touch panel 831 or near the touch panel 831 using any suitable object or accessory such as a finger, a stylus, etc.) and drive the corresponding connection device according to a preset program. Alternatively, the touch panel 831 may include two portions, i.e., a touch detection device and a touch controller. The touch detection device detects the touch direction of a user, detects a signal brought by touch operation and transmits the signal to the touch controller; the touch controller receives touch information from the touch sensing device, converts it to touch point coordinates, and sends the touch point coordinates to the processor 880, and can receive and execute commands from the processor 880. In addition, the touch panel 831 may be implemented by various types such as a resistive type, a capacitive type, an infrared ray, and a surface acoustic wave. The input unit 830 may include other input devices 832 in addition to the touch panel 831. In particular, other input devices 832 may include, but are not limited to, one or more of a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, a joystick, and the like.

The display unit 840 may be used to display information input by the user or information provided to the user and various menus of the cellular phone. The Display unit 840 may include a Display panel 841, and the Display panel 841 may be configured in the form of a Liquid Crystal Display (LCD), an Organic Light-Emitting Diode (OLED), or the like, as an option. Further, touch panel 831 can overlay display panel 841, and when touch panel 831 detects a touch operation thereon or nearby, communicate to processor 880 to determine the type of touch event, and processor 880 can then provide a corresponding visual output on display panel 841 based on the type of touch event. Although in fig. 8, the touch panel 831 and the display panel 841 are two separate components to implement the input and output functions of the mobile phone, in some embodiments, the touch panel 831 and the display panel 841 may be integrated to implement the input and output functions of the mobile phone.

The handset may also include at least one sensor 850, such as light sensors, motion sensors, and other sensors. Specifically, the light sensor may include an ambient light sensor that adjusts the brightness of the display panel 841 according to the brightness of ambient light, and a proximity sensor that turns off the display panel 841 and/or the backlight when the mobile phone is moved to the ear. As one of the motion sensors, the accelerometer sensor can detect the magnitude of acceleration in each direction (generally, three axes), can detect the magnitude and direction of gravity when stationary, and can be used for applications of recognizing the posture of a mobile phone (such as horizontal and vertical screen switching, related games, magnetometer posture calibration), vibration recognition related functions (such as pedometer and tapping), and the like; as for other sensors such as a gyroscope, a barometer, a hygrometer, a thermometer, and an infrared sensor, which can be configured on the mobile phone, further description is omitted here.

Audio circuitry 860, speaker 861, microphone 862 may provide an audio interface between the user and the handset. The audio circuit 860 can transmit the electrical signal converted from the received audio data to the speaker 861, and the electrical signal is converted into a sound signal by the speaker 861 and output; on the other hand, the microphone 862 converts collected sound signals into electrical signals, which are received by the audio circuit 860 and converted into audio data, which are then processed by the audio data output processor 880 and transmitted to, for example, another cellular phone via the RF circuit 810, or output to the memory 820 for further processing.

Wi-Fi belongs to short-distance wireless transmission technology, and the mobile phone can help a user to receive and send e-mails, browse webpages, access streaming media and the like through the Wi-Fi module 870, and provides wireless broadband internet access for the user. Although fig. 8 shows the Wi-Fi module 870, it is understood that it does not belong to the essential constitution of the handset and may be omitted entirely as needed within the scope not changing the essence of the invention.

The processor 880 is a control center of the mobile phone, connects various parts of the entire mobile phone using various interfaces and lines, and performs various functions of the mobile phone and processes data by operating or executing software programs and/or modules stored in the memory 820 and calling data stored in the memory 820, thereby integrally monitoring the mobile phone. Optionally, processor 880 may include one or more processing units; preferably, the processor 880 may integrate an application processor, which mainly handles operating systems, user interfaces, applications, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into processor 880.

The handset also includes a power supply 890 (e.g., a battery) for powering the various components, which may preferably be logically coupled to the processor 880 via a power management system to manage charging, discharging, and power consumption.

Although not shown, the mobile phone may further include a camera, a bluetooth module, etc., which are not described herein.

In an embodiment of the present application, the RF circuit 810 is configured to receive radio frequency signals corresponding to a first frequency point, which are sent at least twice, through a first preset number of channels;

a processor 880, configured to screen out a second preset number of radio frequency signals from the first preset number of radio frequency signals, where the second preset number is smaller than the first preset number;

RF circuit 810, further configured to feed back an acknowledgement ACK signal; and receiving the service data sent according to the ACK signal.

Optionally, the terminal device includes a channel board and a service board, where the service board includes a first FPGA and a second FPGA, one end of the first FPGA is connected to the ADC, and the other end of the first FPGA is connected to the DAC, a pin of the second FPGA is set to a high resistance, and input and output pins of the first FPGA and the second FPGA are consistent;

the processor 880 is specifically configured to process the radio frequency signals of the first preset number through the channel board by using the first analog-to-digital converter ADC to obtain intermediate frequency signals of the first preset number; the intermediate frequency signals of the first preset number are transmitted to the second FPGA through the first FPGA; and screening out a second preset number of intermediate frequency signals from the first preset number of intermediate frequency signals through the first FPGA and the second FPGA.

Optionally, the processor 880 is further configured to equally divide the second preset number of intermediate frequency signals by using the first FPGA and the second FPGA, and perform signal detection by using a fast fourier transform FFT to obtain a signal detection result; selecting a target channel according to the signal detection result; changing the center frequency of the channel board to correspond to the target channel;

the RF circuit 810 is specifically configured to receive the traffic data transmitted according to the ACK signal through the target channel.

Optionally, the RF circuit 810 is specifically configured to receive, through a first preset number of channels, radio frequency signals corresponding to a first frequency point sent at least twice by using a 4-fold oversampling algorithm;

the RF circuit 810 is specifically configured to receive the traffic data transmitted according to the ACK signal by using an 8-fold oversampling algorithm.

In an embodiment of the present application, the RF circuit 810 is configured to send a radio frequency signal corresponding to a first frequency point at least twice, where the radio frequency signal corresponding to the first frequency point is used to filter radio frequency signals; receiving an Acknowledgement (ACK) signal; and sending service data according to the ACK signal.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can store or a data storage device, such as a server, a data center, etc., that is integrated with one or more available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. A frequency selection method based on medium-long wave communication is characterized by comprising the following steps:

receiving radio frequency signals corresponding to a first frequency point which are transmitted at least twice through a first preset number of channels;

feeding back an Acknowledgement (ACK) signal;

and receiving the service data sent according to the ACK signal.

2. The method according to claim 1, wherein the method is applied to a terminal device, the terminal device comprises a channel board and a service board, the service board comprises a first FPGA and a second FPGA, one end of the first FPGA is connected with an analog-to-digital converter (ADC), the other end of the first FPGA is connected with a digital-to-analog converter (DAC), a pin of the second FPGA is set to be high impedance, and input and output pins of the first FPGA and the second FPGA are consistent;

screening out a second preset number of radio frequency signals from the first preset number of radio frequency signals, wherein the screening out the second preset number of radio frequency signals comprises the following steps:

processing the radio frequency signals of the first preset number by using the first analog-to-digital converter (ADC) through the channel board to obtain intermediate frequency signals of the first preset number;

the intermediate frequency signals of the first preset number are transmitted to the second FPGA through the first FPGA;

and screening out a second preset number of intermediate frequency signals from the first preset number of intermediate frequency signals through the first FPGA and the second FPGA.

3. The method of claim 2, further comprising:

equally dividing the second preset number of intermediate frequency signals through the first FPGA and the second FPGA, and performing signal detection by using Fast Fourier Transform (FFT) to obtain a signal detection result;

selecting a target channel according to the signal detection result;

changing the center frequency of the channel board to correspond to the target channel;

the receiving the service data sent according to the ACK signal includes:

and receiving the service data sent according to the ACK signal through the target channel.

4. The method according to any one of claims 1 to 3, wherein the receiving, through a first preset number of channels, the radio frequency signals corresponding to the first frequency point sent at least twice includes:

receiving radio frequency signals corresponding to a first frequency point sent at least twice by adopting a 4-time oversampling algorithm through a first preset number of channels;

the receiving the service data sent according to the ACK signal includes:

and receiving the service data sent according to the ACK signal by adopting an 8-time oversampling algorithm.

5. The method according to any of claims 1-3, wherein the second predetermined number of channel frequencies is 50 bytes/min or 11 bytes/min.

6. The method according to any one of claims 1-5, wherein the terminal device comprises a channel board, a service board and a main control board;

7. A frequency selection method based on medium-long wave communication is characterized by comprising the following steps:

receiving an Acknowledgement (ACK) signal;

and sending service data according to the ACK signal.

8. The method of claim 7, wherein the first frequency point is selected based on empirical data including at least one of historical spectral data, empirically available frequency bands, and geographic location.

9. A terminal device, comprising:

10. A terminal device, comprising:

11. A terminal device, comprising:

a memory storing executable program code;

a processor and transceiver coupled with the memory;

the processor calls the executable program code stored in the memory so that the processor and the transceiver respectively correspondingly execute the method according to any one of claims 1-6, or 7 or 8.

12. A computer-readable storage medium comprising instructions that, when executed on a processor, cause the processor to perform the method of any one of claims 1-6, or 7 or 8.