A method for suppressing mutual interference in full-duplex network

Abstract

The present invention discloses a method for suppressing mutual interference in a full-duplex network, comprising the following steps: S1. Terminal A and Terminal C simultaneously send uplink signals to a full-duplex base station B, with carrier frequencies f1 and f2 respectively; S2. Full-duplex base station B receives uplink signals sent by Terminal A and Terminal C at carrier frequencies f1 and f2 respectively, and performs amplitude modulation and phase modulation on the uplink signals received from Terminal A and Terminal C to obtain mutual interference pre-correction signals; then, full-duplex base station B sends mixed signals of downlink communication signals and mutual interference pre-correction signals to Terminal A and Terminal C at carrier frequencies f2 and f1 respectively, and realizes mutual interference suppression of the full-duplex network in the spatial domain; S3. Terminal A and Terminal C receive downlink signals respectively. The present invention provides a method for suppressing mutual interference in a full-duplex network, which can reduce mutual interference between nodes in a full-duplex network, and has important guiding significance for the practical engineering application of full-duplex communication networking.

Description

Technical Field

[0001] The invention relates to the field of interference suppression, and in particular to a method for suppressing mutual interference in a full-duplex network. Background Art

[0002] Full-duplex networking technology supports each network node to transmit and receive signals at the same time slot and frequency, which can greatly improve network throughput and spectrum utilization, and has therefore attracted widespread attention. The application of full-duplex networking technology is limited by the mutual interference problem between nodes caused by simultaneous and co-frequency transmission of uplink and downlink links.

[0003] To address the mutual interference problem in full-duplex networks, existing research focuses on reducing the mutual interference power at the receiving end to below the demodulation threshold from the perspectives of cell planning, channel allocation, and power control. However, there are problems such as high complexity of multiple access multiplexing, power control affecting communication quality, and only reducing the impact but not eliminating mutual interference.

[0004] In view of the above problems, the present invention proposes a mutual interference distributed nulling algorithm: the full-duplex base station adjusts the amplitude and phase of the received signal, and mixes the obtained signal with the information to be transmitted to obtain a mutual interference pre-correction signal; the mutual interference pre-correction signal and the far-end mutual interference signal are canceled in the spatial domain, ensuring that the user terminal can receive the base station information with high quality. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a new full-duplex network mutual interference suppression method, which uses full-duplex base stations to cancel mutual interference in the spatial domain, ensuring that user terminals can receive base station information with high quality.

[0006] The purpose of the present invention is achieved through the following technical solution: A full-duplex network mutual interference suppression method comprises the following steps:

[0007] S1. Terminal A and terminal C simultaneously send uplink signals to full-duplex base station B, with carrier frequencies f1 and f2 respectively;

[0008] S2. The full-duplex base station B receives the uplink signals sent by the terminal A and the terminal C at carrier frequencies f1 and f2, respectively, and performs amplitude and phase modulation on the uplink signals received from the terminal A and the terminal C to obtain mutual interference pre-correction signals; then, the full-duplex base station B sends a mixed signal of the downlink communication signal and the mutual interference pre-correction signal to the terminal A and the terminal C at carrier frequencies f2 and f1, respectively, to realize mutual interference suppression of the full-duplex network in the spatial domain.

[0009] S3. Terminal A and terminal C receive downlink signals respectively, and the carrier frequencies are f2 and f1 respectively.

[0010] Furthermore, the step S1 includes the following sub-steps:

[0011] S101. The full-duplex hybrid networking scenario includes terminal A, terminal C, and base station B. Considering the limited signal processing capability at the terminals, both terminals use frequency division half-duplex mode for data transmission and do not have the ability to suppress self-interference; base station B uses simultaneous same-frequency full-duplex communication mode and has the ability to suppress self-interference.

[0012] S102. Terminal A and terminal C simultaneously send uplink signals to full-duplex base station B, with carrier frequencies f1 and f2 respectively, and equivalent baseband forms S A (t) and S C (t).

[0013] Furthermore, the step S2 comprises:

[0014] S201. Full-duplex base station B receives uplink signals sent by terminal A and terminal C at carrier frequencies f1 and f2 respectively. The signal received from terminal A can be expressed as The signal received from terminal C can be expressed as in and Respectively represent nodes and Propagation delay and fading between them.

[0015] S202. The uplink signal received from terminal A and terminal C is modulated in amplitude and phase to obtain a mutual interference pre-correction signal; the pre-correction signal for correcting the mutual interference at terminal A can be expressed as The pre-correction signal used to correct the mutual interference at terminal C can be expressed as

[0016] S203. The full-duplex base station B sends a mixed signal of a downlink communication signal and a mutual interference pre-correction signal to the terminal A and the terminal C at carrier frequencies f2 and f1, respectively, to achieve mutual interference suppression of the full-duplex network in the spatial domain. The mixed transmission signal can be expressed as:

[0017]

[0018] Furthermore, the step S3 comprises:

[0019] Terminal A and terminal C receive downlink signals respectively, with carrier frequencies f2 and f1 respectively. At terminal A, the received signal can be expressed as

[0020]

[0021] At terminal C, the received signal can be expressed as

[0022]

[0023] In actual communication scenarios, satisfying τ CA ≈τ CB +τ BA , τ AC ≈τ BC +τ AB , and thus it can be obtained that the power of the residual mutual interference signal in the received signal at terminal A and terminal C is approximately equal to zero, that is, the mutual interference in the full-duplex network is effectively suppressed.

[0024] The beneficial effects of the present invention are: the present invention proposes a new full-duplex network mutual interference suppression method, which utilizes full-duplex base stations to perform mutual interference cancellation in the spatial domain, ensuring that user terminals can receive base station information with high quality, and has important guiding significance for the actual engineering application of full-duplex communication networking. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart of the method of the present invention;

[0026] Figure 2 The constellation diagram for sending and receiving signals in full-duplex networking. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0028] like Figure 1 As shown, a method for suppressing mutual interference in a full-duplex network comprises the following steps:

[0029] S1. Terminal A and terminal C simultaneously send uplink signals to full-duplex base station B, with carrier frequencies f1 and f2 respectively;

[0030] S2. The full-duplex base station B receives the uplink signals sent by the terminal A and the terminal C at carrier frequencies f1 and f2, respectively, and performs amplitude modulation and phase modulation on the uplink signals received from the terminal A and the terminal C to obtain the mutual interference pre-correction signals; then, the full-duplex base station B sends the mixed signals of the downlink communication signals and the mutual interference pre-correction signals to the terminal A and the terminal C at carrier frequencies f2 and f1, respectively, to realize the mutual interference suppression of the full-duplex network in the spatial domain;

[0031] S3. Terminal A and terminal C receive downlink signals respectively, and the carrier frequencies are f2 and f1 respectively.

[0032] Furthermore, the step S1 comprises:

[0033] S101. The full-duplex hybrid networking scenario includes terminal A, terminal C, and base station B. Considering the limited signal processing capability at the terminals, both terminals use frequency division half-duplex mode for data transmission and do not have the ability to suppress self-interference; base station B uses simultaneous same-frequency full-duplex communication mode and has the ability to suppress self-interference.

[0034] S102. Terminal A and terminal C simultaneously send uplink signals to full-duplex base station B, with carrier frequencies f1 and f2 respectively, and equivalent baseband forms S A (t) and S C (t).

[0035] Furthermore, the step S2 comprises:

[0036] S201. Full-duplex base station B receives uplink signals sent by terminal A and terminal C at carrier frequencies f1 and f2 respectively. The signal received from terminal A can be expressed as The signal received from terminal C can be expressed as in and Respectively represent nodes and

[0037] Propagation delay and fading between them.

[0038] S202. The uplink signal received from terminal A and terminal C is modulated in amplitude and phase to obtain a mutual interference pre-correction signal; the pre-correction signal for correcting the mutual interference at terminal A can be expressed as The pre-correction signal used to correct the mutual interference at terminal C can be expressed as

[0039] S203. The full-duplex base station B sends a mixed signal of a downlink communication signal and a mutual interference pre-correction signal to the terminal A and the terminal C at carrier frequencies f2 and f1, respectively, to achieve mutual interference suppression of the full-duplex network in the spatial domain. The mixed transmission signal can be expressed as:

[0040]

[0041] Furthermore, the step S3 comprises:

[0042] S301. Terminal A and terminal C receive downlink signals respectively. At terminal A, the received signal can be expressed as

[0043]

[0044] At terminal C, the received signal can be expressed as

[0045]

[0046] In the embodiments of the present application, the mutual interference suppression effect of the present application is analyzed from two perspectives: theory and simulation:

[0047] From a theoretical perspective, the mutual interference power levels at terminals A and C can be observed: Considering that the propagation delay difference of narrowband signals is much smaller than the baseband symbol period, that is, and S A (t-τ AB -τ B ) C ≈S( A t-τ) A And S C (t-τ CB -τ BA )≈S C (t-τ CA ). Then at terminals A and C, the received signal can be simplified to

[0048]

[0049] Among them, w A (t), w B (t) is the thermal noise at terminals A and C, is the baseband symbol period. It can be found that the mutual interference between terminal A and terminal C is effectively suppressed.

[0050] In the example of the present application, the mutual interference suppression performance of the full-duplex network proposed by the present invention is simulated and verified from the simulation perspective using the MATLAB tool, and the simulation parameters are set as follows:

[0051]

[0052] The full-duplex network signal constellation diagram is as follows Figure 2 As shown. In the traditional scheme, the transmission signal of the full-duplex base station is a pure 16QAM signal; it can be found that the received signal at the user terminal contains the desired signal, mutual interference and thermal noise. In the scheme proposed by the present invention, the transmission signal of the full-duplex base station is a 16QAM signal superimposed with a mutual interference pre-correction signal; it can be found that the received signal at the user terminal only contains the desired signal and thermal noise, and the mutual interference between nodes is effectively suppressed.

[0053] In summary, in order to solve the mutual interference problem between nodes in full-duplex networks, this paper proposes a new full-duplex network mutual interference suppression method, which ensures that the user terminal can receive base station information with high quality. The simulation results preliminarily verify the effectiveness and feasibility of this method.

[0054] The present invention has been described in detail herein by way of specific embodiments, and the description of the above embodiments is provided to enable those skilled in the art to make or apply the present invention, and various modifications of these embodiments will be readily understood by those skilled in the art. The present invention is not limited to these examples, or certain aspects thereof. The scope of the present invention is described in detail by the appended claims.

[0055] The above description shows and describes a preferred embodiment of the present invention, but as mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. And the changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for suppressing mutual interference in a full-duplex network, characterized in that: The following steps are involved: S1. Terminal A and terminal C simultaneously send uplink signals to full-duplex base station B, with carrier frequencies f1 and f2 respectively; S2. The full-duplex base station B receives the uplink signals sent by the terminal A and the terminal C at carrier frequencies f1 and f2, respectively, and performs amplitude modulation and phase modulation on the uplink signals received from the terminal A and the terminal C to obtain the mutual interference pre-correction signals; then, the full-duplex base station B sends the mixed signals of the downlink communication signals and the mutual interference pre-correction signals to the terminal A and the terminal C at carrier frequencies f2 and f1, respectively, to realize the mutual interference suppression of the full-duplex network in the spatial domain; The step S2 comprises: S201. Full-duplex base station B receives uplink signals sent by terminal A and terminal C at carrier frequencies f1 and f2 respectively: The signal received from terminal A is expressed as The signal received from terminal C is expressed as in and Respectively represent nodes and Propagation delay and fading between them; S A (t), S C (t) respectively represent the equivalent baseband forms of terminal A and terminal C simultaneously sending uplink signals to full-duplex base station B; S202. The uplink signal received from terminal A and terminal C is modulated in amplitude and phase to obtain a mutual interference pre-correction signal; the pre-correction signal for correcting the mutual interference at terminal A is expressed as The pre-correction signal used to correct the mutual interference at terminal C is expressed as S203. The full-duplex base station B sends a mixed signal of a downlink communication signal and a mutual interference pre-correction signal to the terminal A and the terminal C at carrier frequencies f2 and f1, respectively, to achieve mutual interference suppression of the full-duplex network in the spatial domain. The mixed transmission signal is expressed as: S3. Terminal A and terminal C receive downlink signals respectively, and the carrier frequencies are f2 and f1 respectively.

2. A full-duplex network mutual interference suppression method according to claim 1, characterized in that: The step S1 comprises the following sub-steps: S101. Assume that a full-duplex hybrid networking scenario includes terminal A, terminal C, and base station B. Terminal A and terminal C both use frequency division half-duplex mode for data transmission; base station B uses simultaneous co-frequency full-duplex communication mode; S102. Terminal A and terminal C simultaneously send uplink signals to full-duplex base station B, with carrier frequencies f1 and f2 respectively, and equivalent baseband forms S A (t) and S C (t).

3. A full-duplex network mutual interference suppression method according to claim 1, characterized in that: The step S3 comprises: Terminal A and terminal C receive downlink signals respectively, with carrier frequencies f2 and f1 respectively. At terminal A, the received signal is expressed as: At terminal C, the received signal is expressed as: In actual communication scenarios, τ CA ≈τ CB +τ BA , τ AC ≈τ BC +τ AB , the power of the residual mutual interference signal in the received signal at terminal A and terminal C is approximately equal to zero, that is, the mutual interference in the full-duplex network is effectively suppressed.

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