CN113645245B - DM-OFDM system physical layer security realization method and device for enhancing robustness - Google Patents
DM-OFDM system physical layer security realization method and device for enhancing robustness Download PDFInfo
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Abstract
The invention discloses a DM-OFDM system physical layer security realization method and a device for enhancing robustness, wherein the method comprises the following steps: mapping the subcarrier serial numbers by utilizing a codebook based on the frequency domain channel factor phase to realize the physical layer safety of the dual-mode index modulation part; and carrying out phase rotation on the data symbol carried by the subcarrier by using the quantized channel factor phase, thereby realizing the physical layer safety of the data symbol modulation part. The method can improve the reliability and robustness of the physical layer safety under the condition of channel estimation errors.
Description
Technical Field
The invention relates to the technical field of communication, in particular to a method and a device for realizing the security of a physical layer of a DM-OFDM system for enhancing robustness.
Background
In the conventional communication process, a high-level data encryption mode is generally adopted to ensure the security of user communication. In recent years, physical layer security has received increasing attention as a necessary supplementary measure. The safety of the system can be greatly improved by adding artificial noise and other simple modes.
Index modulation, on the other hand, is a complementary measure to classical modulation methods, and also attracts a large amount of eye light. For a classical OFDM (Orthogonal Frequency Division Multiplexing) system, the spectral efficiency performance of the system can be further improved by introducing Dual-mode Index Modulation (DM).
The DM-OFDM system can realize further improvement of the system security performance through the related technology of physical layer security. However, the existing work related to this aspect is very little, and there is a relatively strict requirement on the accuracy of channel estimation of a legal communication receiving end, which will limit the communication performance in the practical application process, and is not favorable for improving the robustness of the system.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.
Therefore, an object of the present invention is to provide a DM-OFDM system physical layer security implementation method for enhancing robustness, which can implement physical layer security of a DM-OFDM system and has better robustness.
Another objective of the present invention is to provide a DM-OFDM system physical layer security implementation apparatus with enhanced robustness.
In order to achieve the above object, an embodiment of an aspect of the present invention provides a method for implementing security of a physical layer of a DM-OFDM system, where the method includes the following steps:
mapping the subcarrier serial numbers by utilizing a codebook based on the frequency domain channel factor phase, and carrying out physical layer security of the dual-mode index modulation part;
and carrying out phase rotation on the data symbols carried by the subcarriers by utilizing the quantized channel factor phase, and carrying out physical layer security of a data symbol modulation part.
The DM-OFDM system physical layer safety realization method for enhancing robustness of the embodiment of the invention reduces the requirement on channel estimation by utilizing the phase information of the channel estimation to carry out physical layer safety design on the premise of ensuring higher error rate of an eavesdropper, thereby enhancing the robustness on the premise of ensuring the safety of the system physical layer.
In addition, the DM-OFDM system physical layer security implementation method for enhancing robustness according to the above embodiment of the present invention may further have the following additional technical features:
further, in an embodiment of the present invention, the mapping subcarrier numbers by using a codebook based on a frequency domain channel factor phase includes: and sequentially ordering the phases of the channel factors corresponding to the subcarriers to obtain the mapping function.
Further, in an embodiment of the present invention, the method further includes:
generating a phase from all possible channel factor phases;
and quantizing the phase to obtain a quantized channel factor phase.
In order to achieve the above object, another embodiment of the present invention provides an apparatus for implementing physical layer security of a DM-OFDM system with enhanced robustness, including:
the first design module is used for mapping subcarrier serial numbers by utilizing a codebook based on frequency domain channel factor phases and carrying out physical layer security of the dual-mode index modulation part;
and the second design module is used for performing phase rotation on the data symbol carried by the subcarrier by using the quantized channel factor phase and performing physical layer security of the data symbol modulation part.
The DM-OFDM system physical layer safety realization device for enhancing robustness of the embodiment of the invention reduces the requirement on channel estimation by utilizing the phase information of the channel estimation to carry out physical layer safety design on the premise of ensuring higher error rate of an eavesdropper, thereby enhancing the robustness on the premise of ensuring the safety of the system physical layer.
In addition, the device for implementing the physical layer security of the DM-OFDM system with enhanced robustness according to the above embodiment of the present invention may further have the following additional technical features:
further, in an embodiment of the present invention, the mapping subcarrier numbers by using a codebook based on a frequency domain channel factor phase includes: and sequentially ordering the phases of the channel factors corresponding to the subcarriers to obtain the mapping function.
Further, in an embodiment of the present invention, the method further includes: a generating module, configured to generate a phase according to all possible channel factor phases; and quantizing the phase to obtain a quantized channel factor phase.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a flow diagram of a method for implementing security of a physical layer of a DM-OFDM system with enhanced robustness according to an embodiment of the invention;
FIG. 2 is a diagram illustrating a DM portion physical layer security performance simulation according to an embodiment of the invention;
FIG. 3 is a diagram illustrating DSM section physical layer security performance simulation, in accordance with one embodiment of the invention;
FIG. 4 is a diagram illustrating an overall physical layer security performance simulation according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of a device for implementing security of a physical layer of a DM-OFDM system with enhanced robustness according to an embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
The symbol specification of the proposed robustness-enhanced DM-OFDM system physical layer security implementation method according to the embodiments of the present application will be described first with reference to the accompanying drawings. Alice and a legal receiver Bob adopt the system to carry out normal communication, but the monitoring of an illegal eavesdropper Eve exists. The system uses N sub-carriers for communication, the sub-carriers are divided into G groups, each group has
And (4) sub-carriers. In each group of subcarriers, the data symbols carried by k subcarriers are selected from the group consisting of M A Set of constellation points of
And the data symbols carried by the n-k sub-carriers are selected from the group consisting of M B Set of constellation points of
The total number of feasible index modulation modes is
For each mode l, there are two sets of index modulations
The mode of each group of index modulation is denoted as l g . The frequency domain symbol that each group of subcarriers wishes to transmit may be denoted as x g ＝[x g，1 ，x g，2 ，…，x g，n ]Satisfy the following requirements
And for each subcarrier i in the group, the corresponding channel response factor in the frequency domain is H g (i) In that respect For the sake of simplicity of notation, H is referred to here and hereafter g (i) Are obtained by channel estimation and may deviate from the actual channel response factor.
Direct transmission of x g Cannot guarantee the physical layer security, therefore, it needs to be applied to x g Some physical layer security processing is performed. In the examples of the present application, first, x is paired g Physical layer security implementation of DM layer
Then to
Performing DSM (Data Symbol Modulation) level physical layer security implementation to obtain final transmitted OFDM Symbol x' g ＝[x′ g，1 ，x′ g，2 ，…，x′ g，n ]。
The method and the device for implementing the DM-OFDM system physical layer security with enhanced robustness according to the embodiments of the present invention are described below with reference to the accompanying drawings.
First, a method for implementing security of a physical layer of a DM-OFDM system with enhanced robustness according to an embodiment of the present invention will be described with reference to the accompanying drawings.
Fig. 1 is a flow chart of a method for implementing the physical layer security of the DM-OFDM system with enhanced robustness according to an embodiment of the present invention.
As shown in fig. 1, the method for implementing the security of the physical layer of the DM-OFDM system with enhanced robustness includes the following steps:
in step S101, the subcarrier numbers are mapped by using a codebook based on the phase of the frequency domain channel factor, and the physical layer security of the dual-mode index modulation part is performed.
Specifically, for index subscripts corresponding to the DM, the embodiments of the present application do not use a method directly corresponding to natural subcarrier subscripts, but add a layer of mapping corresponding to one another. This mapping function is denoted as S ═ S (1), S (2),.... multidot.s (n)]And S (i) represents the subcarrier sequence number corresponding to the ith index sequence number. For example, if
The original symbols transmitted on the sub-carrier with natural sequence number S (2) should be taken from
Further, in the embodiment of the present application, the mapping function is obtained by sequentially ordering the phases of the channel factors corresponding to the subcarriers. Namely: is provided with
The mapping function is according to phi g (S(1))≥φ g (S(2))≥…≥φ g (S (n)) can be obtained.
Further, can obtain
In step S102, the quantized phase of the channel factor is used to perform phase rotation on the data symbol carried by the subcarrier, so as to perform physical layer security of the data symbol modulation part.
Optionally, in an embodiment of the present invention, the method further includes:
generating a phase from all possible channel factor phases;
and quantizing the phase to obtain a quantized channel factor phase.
Specifically, first, the embodiments of the present application start with all possible lettersTrack factor phase phi g ＝[φ g (k)，k＝1，2，…，n]Generating a phase phi g 。
Further, for phi g Is quantized to theta g . In this embodiment, quantization is performed by dividing [0, 2 π) equally into m intervals whose boundaries are {0, R, respectively 1 ，R 2 ，…，R m-1 2 π }, wherein
θ g Get phi g The left end of the interval, e.g. when m is 4
When it is taken
Then, the data symbols are phase rotated to obtain the actually transmitted symbols as
It should be noted that only one possible θ is given here g The method is exemplified, but not to be construed as limiting the application. In practical application, researchers can align theta according to specific application scenarios g The method of (1) is appropriately replaced and adjusted.
In summary, through steps S101 to S102, a complete DM-OFDM system physical layer security implementation with enhanced robustness can be obtained.
The physical layer security of the present application includes two levels of consideration, namely the DM and DSM sections, which are also implemented separately. And designing the safety of a physical layer by using the result of the frequency domain channel estimation. Specifically, both the DM level and the DSM level physical layer security can be designed by using only the phase estimation result of the frequency domain channel factor.
The simulation verification results of fig. 2, fig. 3, and fig. 4 can prove that, no matter in the DM level, the DSM level, or the implementation level of the whole system, the method provided by the present application can improve the robustness of the system on the premise of ensuring the secure implementation of the physical layer of the system. It should be noted that, assuming that the actual channel condition is unknown, only biased channel state information can be obtained through channel estimation. The physical layer security is characterized in that a system which does not realize the physical layer security is relatively realized, and the error rate difference between an eavesdropper (Eve) and a legal receiver (Bob) is obviously increased; the robustness is characterized in that compared with a classical physical layer security implementation scheme, the error rate of a legal receiver (Bob) is obviously reduced.
According to the DM-OFDM system physical layer safety realization method for enhancing robustness provided by the embodiment of the invention, on the premise of ensuring higher bit error rate of an eavesdropper, the requirement on channel estimation is reduced by carrying out physical layer safety design by utilizing the phase information of the channel estimation, so that the robustness is enhanced on the premise of ensuring the safety of the system physical layer.
The proposed device for implementing the physical layer security of the DM-OFDM system with enhanced robustness according to the embodiments of the present invention will be described with reference to the accompanying drawings.
Fig. 5 is a schematic structural diagram of a device for implementing security of a physical layer of a DM-OFDM system with enhanced robustness according to an embodiment of the present invention.
As shown in fig. 5, the device for implementing the enhanced robustness DM-OFDM system physical layer security comprises: a first design module 501 and a second design module 502.
The first design module 501 is configured to map subcarrier numbers by using a codebook based on a frequency domain channel factor phase, and perform physical layer security of the dual-mode index modulation part. The second design module 502 is configured to perform phase rotation on a data symbol carried by a subcarrier by using the quantized channel factor phase, and perform physical layer security of a data symbol modulation part.
Optionally, in an embodiment of the present application, mapping subcarrier numbers using a codebook based on a frequency domain channel factor phase includes: and sequentially ordering the phases of the channel factors corresponding to the subcarriers to obtain the mapping function.
Optionally, in an embodiment of the present application, the method further includes: a generating module for generating a phase according to all possible channel factor phases; and quantizing the phase to obtain a quantized channel factor phase.
It should be noted that the foregoing explanation of the method embodiment is also applicable to the apparatus of this embodiment, and is not repeated herein.
According to the DM-OFDM system physical layer safety realization device for enhancing robustness provided by the embodiment of the invention, on the premise of ensuring higher bit error rate of an eavesdropper, the requirement on channel estimation is reduced by carrying out physical layer safety design by utilizing the phase information of the channel estimation, so that the robustness is enhanced on the premise of ensuring the safety of the system physical layer.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (6)
1. A DM-OFDM system physical layer security realization method for enhancing robustness is characterized by comprising the following steps:
mapping the subcarrier serial numbers by utilizing a codebook based on the frequency domain channel factor phase to realize the physical layer safety of the dual-mode index modulation part;
and carrying out phase rotation on the data symbol carried by the subcarrier by using the quantized channel factor phase, thereby realizing the physical layer safety of the data symbol modulation part.
2. The method of claim 1, wherein the mapping subcarrier numbers using the codebook based on the phase of the frequency domain channel factor comprises: and sequentially ordering the phases of the channel factors corresponding to the subcarriers to obtain the mapping function.
3. The method of claim 1, further comprising:
generating a phase from all possible channel factor phases;
and quantizing the phase to obtain a quantized channel factor phase.
4. An apparatus for implementing security of physical layer of DM-OFDM system with enhanced robustness, comprising:
the first design module is used for mapping subcarrier serial numbers by utilizing a codebook based on frequency domain channel factor phases to realize the physical layer safety of the dual-mode index modulation part;
and the second design module is used for performing phase rotation on the data symbol carried by the subcarrier by using the quantized channel factor phase to realize the physical layer safety of the data symbol modulation part.
5. The apparatus of claim 4, wherein the mapping subcarrier numbers using the codebook based on the phase of the frequency domain channel factor comprises: and sequentially ordering the phases of the channel factors corresponding to the subcarriers to obtain the mapping function.
6. The apparatus of claim 4, further comprising: a generating module for generating a phase according to all possible channel factor phases; and quantizing the phase to obtain a quantized channel factor phase.
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| US8050335B2 (en) * | 2008-07-10 | 2011-11-01 | Ittiam Systems (P) Ltd. | Equal phase combining technique for a robust OFDM system |
| CN106453190A (en) * | 2016-10-10 | 2017-02-22 | 东南大学 | Multi-user sub-carrier index modulation orthogonal frequency-division multiplexing (SIM-OFDM) transmission method |
| CN107181732B (en) * | 2017-03-22 | 2020-01-17 | 浙江警察学院 | A Physical Layer Security Communication Method Based on Modulation Symbol Phase Rotation |
| CN108684037B (en) * | 2018-04-08 | 2020-03-17 | 西安交通大学 | OFDM (orthogonal frequency division multiplexing) safe transmission method combining subcarrier pairing and signal inversion |
| CN108900456A (en) * | 2018-07-03 | 2018-11-27 | 北京理工大学 | A kind of double mode index modulation Mapping Design method |
| CN110601821B (en) * | 2019-08-07 | 2022-03-01 | 中国人民解放军战略支援部队信息工程大学 | OFDM communication signal physical layer encryption method and device |
| US11743006B2 (en) * | 2019-11-27 | 2023-08-29 | Intel Corporation | Physical uplink control channel design for discrete fourier transform-spread-orthogonal frequency-division multiplexing (DFT-s-OFDM) waveforms |
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| WO2019154447A1 (en) * | 2018-02-09 | 2019-08-15 | Argo Semiconductors Fs Ltd (He 359654) | Wireless communications system employing continuous phase modulation and physical layer security primitives |
| CN110856169A (en) * | 2019-11-22 | 2020-02-28 | 国网河南省电力公司电力科学研究院 | A Physical Layer Security Algorithm Based on Joint Subcarrier Grouping and XOR Operation |
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