A Two-Dimensional Antenna Cancellation Method for Narrowband Full-duplex Systems

Abstract

The invention discloses a 2D antenna cancellation method of a narrowband full-duplex system. N pairs of emission antennas are additionally arranged on the basis of self-interference elimination in the phase offset principle; in the narrowband full-duplex system, the N pairs of emission antennas and one pair of reception antennas form a circular antenna array structure in the near-end full-duplex node, the reception antennas are placed at the circular center, and the emission antennas are distributed in two concentric circles which take the reception antennas as the center, and are distributed on the diameters pairwise; in each pair of emission antennas, the distance from one emission antenna to the circular center is d, the distance from the other emission antenna to the circular center is d+ lambda / 2, the difference between the length of one path and the length of the other path is n times that of the half of the signal carrier wavelength, n represents an odd number, the phase different is pi, and the mutual cancellation principle is met; in the emission antennas, emission signals are divided into N parts by a power divider, and sent in the same frequency; self-interference signals are overlapped in the cancellation manner in the reception antennas, and interference in useful signals at the reception end is obviously reduced.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to a two-dimensional antenna cancellation method of a narrowband full-duplex system. Background technique [0002] The use of wireless devices is becoming more and more common today. The ever-increasing demand for wireless multimedia services and limited wireless spectrum resources, as well as the increasing demand of users for wireless network speed and reliability, make people more and more focused on the development of higher transmission rates and more cost-effective wireless network system. How to improve the utilization of limited spectrum resources is the main research goal of wireless communication systems. In the past few decades, researchers have focused on researching various technologies and methods to save wireless resources or maximize the use of wireless resources. Various wireless communication systems have emerged as the times require. However, ...

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Problems solved by technology

[0009] In theory, there should be But in fact, it is very difficult to ensure the same amplitude of the two sets of signals at the receiving antenna, because the two sets of signals arrive at the receiving antenna through different paths, which will inevitably cause distortion or distortion

If the phase difference of the two sets of transmitted signals is ideal, there will be φ 2 = φ 1 +π, but since we are targeting a narrowband signal, the transmitted signal is not a single frequency, but has a certain bandwidth, and it is an actual system, so there are still amplitude and phase errors

These amplitude matching errors and phase matching errors will affect the performance of the antenna cancellation technology and make it less effective

[0010] We know that whether it is in amplitude matching or phase matching, that is, distance matching, a small error will have a great impact, making the performance of the cancellation technology degrade

At the same time, during the transmission process of the signal from the transmitting antenna to the receiving antenna, different channel characteristics will also seriously affect the amplitude and phase of the signal, resulting in changes in the relative amplitude and phase of the offset signal, resulting in a decline in the performance of the antenna cancellation technology.

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