CN-122026975-A - Flow state antenna assisted downlink direct transmission and cooperative power domain NOMA dual-mode layered communication method

CN122026975ACN 122026975 ACN122026975 ACN 122026975ACN-122026975-A

Abstract

The invention discloses a fluid antenna assisted downlink direct transmission and cooperation power domain NOMA dual-mode layered communication method, which constructs a system, wherein the system executes dual-mode transmission in a transmission period, a source end transmits a first signal to a near end through a first antenna and simultaneously broadcasts NOMA superposition signals through a second antenna, each receiving end utilizes the interference compression function of the fluid antenna to realize signal layered reception, a second period transmits a far-end signal to the near end through the first antenna, the near end and the far end respectively decode based on the maximum signal-to-interference-noise ratio criterion, and the invention realizes zero SIC reception of near end and far end equipment and single SIC reception of cooperation equipment through the fusion design of fluid antenna interference suppression and port selection strategies, thereby obviously reducing imperfect SIC residual interference and effectively improving the speed and reliability of the system.

Inventors

Yuan Kangling
XU YAO
XU TONG
ZHANG ZHIZHONG
LIN PENG
ZHU JIANYUE

Assignees

南京信息工程大学

Dates

Publication Date: 20260512
Application Date: 20260409

Claims (10)

1. A flow state antenna assisted downlink direct transmission and cooperation power domain NOMA dual-mode layered communication method is characterized by comprising the following steps: (1) The method comprises the steps of constructing a downlink communication system comprising source end communication equipment, near end communication equipment, cooperative communication equipment and far end communication equipment, wherein the source end communication equipment is provided with a first conventional fixed transmitting antenna and a second conventional fixed transmitting antenna; (2) The method comprises the steps of dividing an information transmission period into a first period and a second period, transmitting a first signal carrying information required by near-end communication equipment through a first conventional fixed transmitting antenna by source-end communication equipment in the first period, transmitting power domain non-orthogonal multiple access superposition coded signals carrying information required by cooperative communication equipment and far-end communication equipment through a second conventional fixed transmitting antenna at the same time, selecting a receiving port from a plurality of preset receiving ports by the near-end communication equipment based on a maximum signal-to-interference-noise ratio criterion as interference by the superposition coded signals of the second conventional fixed transmitting antenna, directly decoding the first signal without serial interference elimination, selecting the receiving port from the plurality of preset receiving ports by the cooperative communication equipment based on a joint feasibility criterion, performing serial interference elimination on the superposition coded signals, and sequentially decoding the signals required by the far-end communication equipment and the signals required by the cooperative communication equipment; (3) And in a second period, the cooperative communication equipment forwards the signals required by the far-end communication equipment obtained through decoding to the far-end communication equipment, meanwhile, the source-end communication equipment transmits second signals carrying information required by the near-end communication equipment through a first conventional fixed transmitting antenna, the second conventional fixed transmitting antenna is kept silent, the far-end communication equipment selects a receiving port from a plurality of preset receiving ports based on a maximum signal-to-interference-noise ratio criterion, receives and decodes the forwarded signals, and the near-end communication equipment regards the forwarded signals as interference, selects the receiving port from the plurality of preset receiving ports based on the maximum signal-to-interference-noise ratio criterion, and receives and decodes the second signals.
2. The method for fluid antenna assisted direct downlink and cooperative power domain NOMA dual-mode layered communication of claim 1, wherein in step (2), the first period of time and the second period of time are continuous in time and have equal duration.
3. The method for fluid antenna assisted direct downlink and cooperative power domain NOMA dual-mode layered communication according to claim 2, wherein the source communication device adopts an antenna level power allocation mode to allocate total transmission power to the first and second conventional fixed transmission antennas during the first period.
4. A fluid antenna assisted downlink direct transfer and cooperative power domain NOMA dual mode layered communication method according to claim 3, wherein in the power domain non-orthogonal multiple access superposition coded signal transmitted by the second conventional fixed transmitting antenna in the first period, the power allocated to the signal required by the remote communication device is greater than the power allocated to the signal required by the cooperative communication device.
5. The method for performing downlink direct transmission and cooperative power domain NOMA dual-mode layered communication assisted by a fluidized antenna according to claim 1, wherein in step (2), the near-end communication device performs a specific process of selecting a port by using a maximum signal-to-interference-plus-noise ratio criterion in a first period, wherein superposition coded signals of a second conventional fixed transmitting antenna are regarded as interference, receiving signal-to-interference-plus-noise ratios of corresponding first signals of preset receiving ports are calculated respectively, and a preset receiving port with the maximum signal-to-interference-plus-noise ratio is selected as a working port to directly decode the first signals.
6. A fluid antenna assisted downlink direct transmission and cooperative power domain NOMA dual-mode layered communication method is characterized in that in the step (2), a port selection specific process based on a joint feasibility criterion is adopted by cooperative communication equipment in a first period, wherein a first signal of a first conventional fixed transmitting antenna is regarded as interference, decoding signal-to-interference-and-noise ratios of remote communication equipment signals and cooperative communication equipment signals corresponding to preset receiving ports are calculated respectively, an effective port set capable of simultaneously meeting the condition that the remote communication equipment signals and the cooperative communication equipment signals are successfully decoded is screened out according to preset decoding threshold conditions, a preset receiving port which enables the signal decoding signal-to-interference-ratio of the cooperative communication equipment to be maximum is selected from the effective port set to serve as a working port if the effective port set is not empty, and a preset receiving port which enables the signal decoding signal-to-interference-noise ratio of the remote communication equipment to be maximum is selected from all preset receiving ports to serve as the working port if the effective port set is empty.
7. The method for dual-mode hierarchical communication in a downlink direct-transfer and co-power domain NOMA with the assistance of a fluidized antenna according to claim 1, wherein in step (2), the co-operative communication device decodes the signal required by the remote communication device preferentially when performing the serial interference cancellation in the first period, and decodes the signal required by the co-operative communication device.
8. The method for performing downlink direct transmission and cooperative power domain NOMA dual-mode layered communication assisted by a fluid antenna according to claim 1, wherein in step (3), the remote communication device performs a specific process of selecting a port by using a maximum signal-to-interference-and-noise ratio criterion in a second period, wherein the specific process is that decoding signal-to-interference-and-noise ratios of the forwarding signals corresponding to each preset receiving port are calculated respectively, and the preset receiving port with the maximum signal-to-interference-and-noise ratio is selected as a working port to receive and decode the forwarding signals.
9. The method for performing downlink direct transmission and cooperative power domain NOMA dual-mode layered communication assisted by a fluid antenna according to claim 1, wherein in step (3), the near-end communication device performs a specific process of selecting a port by using a maximum signal-to-interference-plus-noise ratio criterion in a second period, wherein a forwarding signal is regarded as interference, decoding signal-to-interference-plus-noise ratios of the second signals corresponding to each preset receiving port are calculated respectively, the preset receiving port with the maximum signal-to-interference-plus-noise ratio is selected as a working port, and the second signals are received and decoded.
10. A fluid antenna assisted downlink direct transmission and cooperation power domain NOMA dual-mode layered communication system is characterized by comprising a source end communication device, a near end communication device, a cooperation communication device and a far end communication device, wherein the source end communication device is provided with a first conventional fixed transmitting antenna and a second conventional fixed transmitting antenna, the near end communication device, the cooperation communication device and the far end communication device are all provided with a single two-dimensional plane fluid antenna, the fluid antenna comprises a plurality of preset receiving ports, only one port is activated at any time, and the system is configured to execute the method of any one of claims 1-9.

Description

Flow state antenna assisted downlink direct transmission and cooperative power domain NOMA dual-mode layered communication method Technical Field The invention relates to the technical field of wireless communication, in particular to a flow state antenna assisted downlink direct transmission and cooperation power domain NOMA dual-mode layered communication method. Background The existing downstream NOMA-based CDRT (NOMA-CDRT) method generally adopts a single-antenna source end transmitting architecture, and a receiving end must rely on a serial interference cancellation technology to separate multi-user signals superimposed on a power domain. In an actual electromagnetic environment, a receiving end is usually faced with the condition of imperfect SIC due to the channel state information acquisition error and hardware nonideal factors. In particular, for near-end communication devices, it is often necessary to demodulate and cancel signals of other communication devices in order to extract the signal required by the near-end communication device. The multistage SIC not only increases the operation load and processing delay of the terminal, but also easily causes cross-stage accumulation and error propagation of residual interference. With the increase of the transmitting power, the problem of performance limitation caused by the residual interference is more remarkable, and the achievable throughput and transmission reliability of the system under limited resources are restricted. On the other hand, the two-dimensional plane Fluid Antenna (FAS) enables the equipment to select the port with the best channel state for receiving and transmitting by arranging a plurality of switchable preset ports in a limited physical space, so that additional space diversity gain can be obtained, and a technical approach is provided for relieving channel fading and improving receiving reliability. However, if only the fluid antenna is applied to the conventional NOMA-CDRT network as a conventional receiving component, the gain is mainly limited to improving the local channel fading condition of the receiving end. Because the source end transmitter still adopts a single antenna power domain superposition transmitting mechanism, the fluid antenna cannot effectively and flexibly isolate and layer the direct transmission link and the cooperative link from the physical structure, and therefore the problem of multistage SIC resolving load and residual interference accumulation caused by the load of the near-end communication equipment cannot be avoided. The prior art architecture is difficult to simultaneously meet the requirements of high spectrum efficiency, wide area coverage and SIC residual interference suppression. Disclosure of Invention The invention aims to provide a fluid antenna assisted downlink direct transmission and cooperation power domain NOMA dual-mode layered communication method, which solves the problems that a single-antenna source end communication equipment architecture is commonly adopted in the existing downlink NOMA-CDRT method and the multi-stage serial interference elimination of a receiving end is relied on, namely, residual interference is easy to accumulate and error propagation is caused under the imperfect SIC condition, so that decoding performance of near-end communication equipment is highly sensitive to SIC errors, thereby limiting the problems of system reliability and reachable throughput, and simultaneously solves the problem that the existing improvement mode which only relies on diversity gain of the receiving end is difficult to effectively isolate power domain superposition interference from the system structural level. The technical scheme is that the flow state antenna assisted downlink direct transmission and cooperation power domain NOMA dual-mode layered communication method comprises the following steps: (1) The method comprises the steps of constructing a downlink communication system comprising source end communication equipment, near end communication equipment, cooperative communication equipment and far end communication equipment, wherein the source end communication equipment is provided with a first conventional fixed transmitting antenna and a second conventional fixed transmitting antenna; (2) The method comprises the steps of dividing an information transmission period into a first period and a second period, transmitting a first signal carrying information required by near-end communication equipment through a first conventional fixed transmitting antenna by source-end communication equipment in the first period, transmitting power domain non-orthogonal multiple access superposition coded signals carrying information required by cooperative communication equipment and far-end communication equipment through a second conventional fixed transmitting antenna at the same time, selecting a receiving port from a plurality of preset receiving ports by the near-end communicati