Multi-order configurable modulation and demodulation method, device and system for private network cellular networking

Abstract

The invention belongs to the technical field of wireless communication, and particularly relates to a multi-order configurable modulation and demodulation method, device and system for private network cellular networking, and the method comprises the following steps: a network control center dynamically configures a modulation and demodulation parameter set, the parameter set comprises a carrier frequency, a symbol rate, a modulation order, a coding scheme and a radio frequency parameter, the modulation and demodulation parameter configuration process meets the following conditions: the time delay of single mode switching is less than or equal to 10ms; parallel differentiation processing of at least four kinds of heterogeneous service flows is supported; the terminal equipment obtains a current modulation and demodulation configuration strategy through the private network signaling channel; according to the service type and the channel quality index, dynamically switching a working mode in a preset N-order modulation and demodulation mode; a software defined radio architecture is adopted to realize real-time reconfiguration of modulation and demodulation parameters. The problem of contradiction among service diversity, channel time-varying characteristics and resource limitation in a private network environment is solved, and millisecond-level dynamic reconstruction of modulation and demodulation parameters is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communication, and particularly relates to a multi-stage configurable modulation and demodulation method, device and system for private network cellular networking. Background Art

[0002] In the currently established power private network systems, there are multiple manufacturers of equipment and multiple technical standards, and each regional subnet operates independently. The management and control systems of each subnet have completed the functions of equipment configuration and network management within a local range, meeting the actual needs to a certain extent, but there are also the following problems. (1) There is no unified data standard for management and control interoperability. There is a lack of a unified northbound management and control interface, and state grid companies, provincial companies, etc. cannot conduct unified equipment monitoring, performance statistics, fault viewing and configuration management of lower-level regions, lacking the ability of unified management. Similarly, the coordinated work of neighboring peer-level regional networks cannot be carried out. (2) There is no unified network management and control system for multi-mode self-organizing network and cellular network. The technologies and systems of EMS, NMS, and UNMS for cellular networks are very mature, and the management methods and systems for self-organizing networks are also relatively mature, but the unified network management and control system for cellular network + self-organizing network targeting actual combat application scenarios is still in the state of being to be developed. A network combining cellular network as the main part and supplemented by self-organizing network has both the economy and rationality of network construction and ensures the necessity and completeness of coverage. It is necessary to centrally present the status of each network element in combination with the actual combat application target and provide management and control of the equipment of each network.

[0003] Currently, there are the following problems in multi-mode networking of cellular networking and self-organizing network: (1) Security issues. The converged network not only integrates the advantages of various networks, but also inevitably brings various security issues into the converged network. Adding a temporary node in the cellular network to represent an intermediate node for forwarding data poses a problem of difficult security information interaction between different mode networkings, causing new problems for data confidentiality and secure transmission. (2) Communication mode switching problem. There are multiple communication modes in multi-mode networking. The flexible selection of communication modes reflects the network self-adaptability. It is necessary to determine a reasonable communication mode switching strategy, comprehensively consider various factors such as the actual service requirements of users and the network status in different scenarios, and determine an effective evaluation mechanism to evaluate the communication quality of different modes to achieve intelligent switching of the communication mode of mobile devices. (3) Equipment issues. The equipment needs to have the ability to communicate with both cellular networking and self-organizing network at the same time. While maintaining the communication of the cellular system, the mobile device also needs to maintain the communication of the self-organizing network, which will increase the energy demand of the mobile device. (4) The traditional modulation and demodulation method of private network is fixed and cannot adapt to dynamic service requirements (such as mixed transmission of video monitoring and sensor data); (5) Existing adaptive modulation technologies (such as LTE-AMC) have problems such as long decision time (>50 ms) and large signaling overhead in private network environments; 6. The dedicated frequency band is severely affected by industrial interference, and existing solutions lack the ability of frequency-domain and time-domain joint anti-interference. Summary of the Invention

[0004] The object of the present invention is to provide a multi - order configurable modulation and demodulation method, device and system for private network cellular networking aiming at the problems existing in the prior art, solve the contradiction among service diversity, channel time - variability and resource limitation in the private network environment, and realize the millisecond - level dynamic reconstruction of modulation and demodulation parameters, which is especially applicable to the dedicated wireless communication networks in industries such as power, emergency, rail transit, etc.

[0005] The technical solution of the present invention is as follows:

[0006] A multi - order configurable modulation and demodulation method for private network cellular networking includes the following steps:

[0007] The network control center dynamically configures a set of modulation and demodulation parameters. The parameter set includes carrier frequency, symbol rate, modulation order, coding scheme and radio frequency parameters. The modulation and demodulation parameter configuration process satisfies: single - mode switching delay ≤ 10 ms; supports parallel differential processing of at least 4 heterogeneous service flows;

[0008] The terminal device obtains the current modulation and demodulation configuration strategy through the private network signaling channel;

[0009] Dynamically switch the working mode among the preset N - order modulation and demodulation modes according to the service type and channel quality index;

[0010] Adopt a software - defined radio architecture to realize the real - time re - configuration of modulation and demodulation parameters.

[0011] Specifically, it further includes an anti - interference processing step:

[0012] Automatically switch to the spread - spectrum modulation mode when interference is detected;

[0013] Dynamically adjust the transmit power spectral density to avoid the interference frequency band.

[0014] Specifically, the dynamic configuration process includes:

[0015] Periodically collect channel state information (CSI) and service QoS requirements;

[0016] Select the optimal modulation and demodulation combination through the preset decision - tree algorithm;

[0017] Use in - band signaling or control channels to distribute configuration instructions.

[0018] Specifically, the N - order modulation and demodulation modes include:

[0019] Basic mode: Adopt QPSK / 8PSK modulation and 1 / 2 code - rate forward error correction coding;

[0020] Enhanced mode: Adopt 16QAM modulation and 3 / 4 rate Turbo coding;

[0021] High-order mode: Adopt 64QAM modulation and LDPC coding;

[0022] Emergency mode: Adopt GMSK modulation and repetition coding.

[0023] A modulation and demodulation device for implementing the method as described above, comprising:

[0024] A programmable baseband processing unit, supporting on-site reconstruction of various digital modulation methods;

[0025] An adaptive radio frequency front end, whose operating frequency band can be software-defined;

[0026] A configuration management module, storing a preset modulation and demodulation strategy matrix.

[0027] Specifically, the programmable baseband processing unit includes:

[0028] A parameterized modulator, supporting configurable M-order QAM / MPSK / APSK;

[0029] A multi-standard compatible codec, supporting dynamic selection of coding schemes.

[0030] A private network cellular system, applying the method as described above, comprising:

[0031] A network management subsystem, including a policy decision-making engine and a configuration database;

[0032] A base station cluster, supporting on-demand loading of multi-order modulation and demodulation parameters;

[0033] A terminal group, having the ability to automatically parse and execute configuration policies.

[0034] The beneficial effects of the present invention are as follows: By carefully analyzing the requirements and characteristics of the power wireless private network cellular networking communication system, the present invention proposes a multi-order configurable modulation and demodulation scheme, which simultaneously supports different channel bandwidths of 25kHz, 50kHz, 100kHz, and 200kHz and different coding rates. According to the real-time characteristics of the channel and the requirements of the power authorized frequency band, the multi-channel aggregation technology is adopted, and modulation methods such as GMSK, QPSK, 16QAM, and 64QAM are introduced to realize the adaptive selection of modulation and demodulation methods. Compared with the fixed modulation and demodulation method, the spectral efficiency is increased by 30%-200% (measured data); 2. The mode switching delay ≤ 5ms (laboratory test conditions); 3. When 10% of the frequency band is interfered, 90% of the basic throughput can still be maintained. Description of the Drawings

[0035] Figure 1It is a schematic diagram of the working process of QPSK / 8PSK modulation of the present invention;

[0036] Figure 2 It is a schematic diagram of the working process of coherent demodulation of QPSK / 8PSK;

[0037] Figure 3 It is a schematic diagram of the working process of 16QAM / 64QAM modulation;

[0038] Figure 4 It is a schematic diagram of the working process of demodulation of 16QAM / 64QAM;

[0039] Figure 5 It is the working process of GMSK modulation;

[0040] Figure 6 It is the working process of 1-bit differential demodulation; Specific implementation manners

[0041] The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0042] Embodiment 1

[0043] This embodiment provides a multi-order configurable modulation and demodulation method for a private network cellular network, including the following steps:

[0044] S1. The network control center dynamically configures a set of modulation and demodulation parameters. The parameter set includes carrier frequency, symbol rate, modulation order, coding scheme, and radio frequency parameters. The modulation and demodulation parameter configuration process satisfies: single-mode switching delay ≤ 10 ms; supports parallel differential processing of at least 4 heterogeneous service flows; the dynamic configuration process includes: periodically collecting channel state information (CSI) and service QoS requirements; selecting the optimal modulation and demodulation combination through a preset decision tree algorithm; distributing configuration instructions using in-band signaling or a control channel.

[0045] S2. The terminal device obtains the current modulation and demodulation configuration strategy through a private network signaling channel;

[0046] S3. Dynamically switch the working mode in a preset N-order modulation and demodulation mode according to the service type and channel quality index. The N-order modulation and demodulation mode includes:

[0047] Basic mode: Adopt QPSK / 8PSK modulation and forward error correction coding with a code rate of 1 / 2;

[0048] Enhanced mode: Adopt 16QAM modulation and Turbo coding with a code rate of 3 / 4;

[0049] High-order mode: Adopt 64QAM modulation and LDPC coding;

[0050] Emergency mode: Adopt GMSK modulation and repeated coding.

[0051] S4. Implement real-time reconfiguration of modulation and demodulation parameters using a software-defined radio architecture.

[0052] According to actual needs, it generally also includes anti-interference processing steps:

[0053] Automatically switch to the spread-spectrum modulation mode when interference is detected;

[0054] Dynamically adjust the transmit power spectral density to avoid interference frequency bands.

[0055] In this embodiment, the basic mode of the N-order modulation and demodulation mode adopts QPSK / 8PSK modulation, and the process block diagram is as Figure 1 shown. When implementing QPSK / 8PSK modulation, after the random data passes through serial-to-parallel conversion, for QPSK, every two bits form a symbol, and for 8PSK, every three bits form an 8PSK symbol. Then, symbol mapping is performed to obtain the phase corresponding to the symbol. I and Q data are generated through interpolation, shaped filtering is performed on the I and Q data, and finally, the I and Q data are multiplied by a pair of orthogonal carriers respectively and then added together to obtain the QPSK / 8PSK modulated signal.

[0056] The QPSK / 8PSK signal adopts the IQ modulation method, and its coherent demodulation working process is as Figure 2 shown. The specific process is as follows: The received signal is coherently demodulated. First, it passes through a low-pass filter, matched filtering, downsampling, and sampling decision to obtain bit information, and then through serial-to-parallel conversion and polarity conversion to obtain the final demodulated signal.

[0057] The modulation process of 16QAM / 64QAM adopted in this embodiment only differs in the symbol mapping link, so the modulation working process is integrated as Figure 3 . When implementing these two modulation methods, after the random data passes through serial-to-parallel conversion and level conversion, for 16QAM, every four bits are used as a symbol, which is mapped through the constellation diagram and shaped filtered, and for 64QAM, every six bits are used as a symbol, which is mapped through the constellation diagram and shaped filtered. Then, the symbols are multiplied by a pair of orthogonal carriers respectively and finally added together to obtain the 16QAM / 64QAM modulated signal.

[0058] The 16QAM / 64QAM signal adopts the IQ modulation method, and its demodulation working process is as Figure 4 shown. The specific process is as follows: After the received signal undergoes carrier recovery, it successively passes through low-pass filtering, multi-level decision, constellation diagram inverse mapping, and level conversion to obtain bit information, and then through serial-to-parallel conversion and polarity conversion to obtain the final demodulated signal.

[0059] Currently, it is more commonly used to directly calculate the Log-Likelihood Ratio (LLR) of each bit in the digital domain based on the constellation diagram and the received data.

[0060] Assume the signal we receive is r, and the formula for the i-th bit after demodulation

[0061]

[0062] This is a ratio of conditional probabilities, that is, when the received signal is r, we infer from the information of the received signal whether the probability that this bit of the transmitted signal is 1 is greater or the probability that it is 0 is greater (inferring the transmission based on the reception).

[0063] Combine different code rates and different modulation orders to adapt to data transmission in different channels and different application conditions.

[0064] For the data after convolutional coding, puncturing is performed according to a specific template, and it is very easy to implement coding with different code rates. Arrange the encoded bits in a specific order, select the bits to be sent in order, and determine the number of selected bit data according to the modulation method and the allocated resources (such as the number of carriers), then rate matching with any rate can be achieved. Taking a fixed puncturing template as an example, for example, the code rates after puncturing are: 1 / 3, 1 / 2, 3 / 4, 5 / 6 four code rates. If the selectable modulation methods are: GMSK, 8PSK, 16QAM, 64QAM, then there are a total of 4 * 4 = 16 modulation coding methods, and one of the modulation coding methods MCS is selected for each data transmission.

[0065] The working process of the GMSK modulation adopted in this embodiment is as Figure 5 shown. The random sequence first undergoes polarity conversion to obtain a bipolar sequence b n , then passes through a Gaussian pre-modulation filter to obtain a smooth signal f(t). Secondly, solve the modulation phase θ(t) corresponding to the GMSK symbol to obtain I / Q two-channel data. Finally, multiply and add the two-channel data with the carrier respectively to obtain the GMSK signal.

[0066] In the implementation process of GMSK modulation, starting from the modulation phase history, there will be a zigzag phase history with frequency jumps, which is transformed into a smooth phase history through a pre-modulation filter. When designing the pre-modulation filter, it should obtain the best out-of-band energy suppression effect of the spectrum at the cost of minimizing inter-symbol interference, and meet the following conditions: (a) good frequency cut-off characteristics; (b) limited impulse response; (c) integral phase satisfies π / 2. The pre-modulation filter mainly considers the Gaussian filter.

[0067] In the implementation of GMSK demodulation, there are various methods such as differential demodulation, coherent demodulation, and despinning. Taking the 1-bit differential demodulation scheme as an example, its working process is as follows. Figure 6 As shown. The received signal x(t) first passes through a band-pass filter to obtain y(t). After y(t) is phase-shifted by π / 2 and delayed by one period T, the resulting signal is multiplied with y(t). Then, the output phase information is filtered by a low-pass filter to remove high-frequency components, and the demodulated output sequence is obtained by using phase information sampling and decision-making. b When GMSK obtains the final output sequence through sampling and decision-making, Viterbi decision is often applied to obtain the demodulated sequence. When implementing Viterbi decision, its steps are "add, compare, and select". By setting the memory length, all possible path metrics within the memory length are calculated, and the surviving path is selected for backtracking to demodulate the initial symbol of the path. Since the number of additional phase states of each GMSK symbol is limited, the number of path state transformations of symbols with a finite length is also limited. Then, the starting point of the path is set to the next symbol of the already-decided symbol, and the steps of "add, compare, and select" are continued to decide subsequent symbols.

[0068] Example 2

[0069] This example provides a modulation and demodulation device for implementing the method described in Example 1, including:

[0070] A programmable baseband processing unit that supports on-site reconfiguration of multiple digital modulation methods, mainly including a parameterized modulator that supports configurable M-QAM / MPSK / APSK; a multi-standard compatible codec that supports dynamic selection of coding schemes, improving the flexibility and compatibility of the system while ensuring performance.

[0071] An adaptive radio frequency front-end with a software-defined operating frequency band, capable of dynamically adjusting operating frequency, bandwidth, filtering characteristics, etc. to meet the communication requirements of multiple frequency bands and multiple modes. This is a key technology, and the implementation methods of the adaptive radio frequency front-end mainly include: 1. SDR architecture (software-defined + programmable hardware); 2. Reconfigurable radio frequency components (filters, PA / LNA, antennas); 3. Dynamic spectrum management (DSA, cognitive radio); 4. Integrated FEM design (multiple frequency bands, low power consumption); 5. AI optimization (intelligent parameter adjustment).

[0072] A configuration management module that stores a preset modulation and demodulation strategy matrix.

[0073] Example 3

[0074] This example provides a private network cellular system that applies the above method, including:

[0075]

[0076] ​Network management subsystem, including a policy decision engine and a configuration database;

[0077] Base station cluster, supporting on-demand loading of multi-level modulation and demodulation parameters;

[0078] Terminal group, with the ability to automatically parse and execute configuration policies.

[0079] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements on some technical features; Without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A multi-stage configurable modulation and demodulation method for private network cellular networking, characterized in that Including the following steps: The network control center dynamically configures a set of modulation and demodulation parameters, and the parameter set includes carrier frequency, symbol rate, modulation order, coding scheme, and radio frequency parameters; The terminal device obtains the current modulation and demodulation configuration strategy through the dedicated network signaling channel; According to the service type and channel quality index, dynamically switch the working mode among the preset N-order modulation and demodulation modes; Adopt a software-defined radio architecture to realize real-time reconfiguration of modulation and demodulation parameters.

2. The multi-order configurable modulation and demodulation method for private network cellular networking according to claim 1, characterized in that, It further includes an anti-interference processing step: Automatically switch to the spread-spectrum modulation mode when interference is detected; Dynamically adjust the transmit power spectral density to avoid the interference frequency band.

3. The multi-order configurable modulation and demodulation method for private network cellular networking according to claim 1, characterized in that, The dynamic configuration process includes: Periodically collect channel state information (CSI) and service QoS requirements; Select the optimal modulation and demodulation combination through a preset decision tree algorithm; Use in-band signaling or control channels to distribute configuration instructions.

4. The multi-stage configurable modulation and demodulation method for private network cellular networking according to claim 1, wherein The N-order modulation and demodulation modes include: Basic mode: Adopt QPSK / 8PSK modulation and 1 / 2 code rate forward error correction coding; Enhanced mode: Adopt 16QAM modulation and 3 / 4 code rate Turbo coding; High-order mode: Adopt 64QAM modulation and LDPC coding; Emergency mode: Adopt GMSK modulation and repetition coding.

5. The multi-stage configurable modulation and demodulation method for a private network cellular network according to claim 1, wherein The private network cellular networking adopts a hierarchical architecture: Core layer: Centralized policy decision-making unit; Convergence layer: Distributed parameter execution nodes; Access layer: A group of terminal devices that support multi-mode switching.

6. A modulation and demodulation device for implementing the method according to any one of claims 1-5, characterized in that, Including: A programmable baseband processing unit that supports on-site reconfiguration of multiple digital modulation methods; An adaptive radio frequency front end whose operating frequency band can be software-defined; A configuration management module that stores a preset modulation and demodulation strategy matrix.

7. The modulation and demodulation device according to claim 6, characterized in that, The programmable baseband processing unit includes: A parameterized modulator that supports M-order QAM / MPSK / APSK configuration; A multi-standard compatible codec that supports dynamic selection of coding schemes.

8. A private network cellular system, applying the method according to any one of claims 1-5, characterized in that, Including: A network management subsystem that includes a policy decision-making engine and a configuration database; A base station cluster that supports on-demand loading of multi-order modulation and demodulation parameters; A terminal group that has the ability to automatically parse and execute configuration policies.

9. The multi-level configurable modulation and demodulation method for private network cellular networking according to claim 1, wherein The modulation and demodulation parameter configuration process satisfies: The single-mode switching delay ≤ 10 ms; Support parallel differential processing of at least 4 heterogeneous service flows.

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