Research On Agricultural Information Transmission Strategy Assisted By Intelligent Reflecting Surface

With the development of agricultural informatization,wireless technology has been widely promoted in monitoring and collecting the agricultural information.Although the application of wireless communication technology has brought many benfits to agriculture informatization,but the transmission remains facing the following two problems:1)A single-antenna receive equipment is always deployed in the large-scale agricultural circumstance,resulting in a low signal-to-noise ratio at the receiver after a long-distance transmission,which is difficult to complete a high-quality reliable transmission for the key data;2)The transmission of agricultural information is seriously affected by the environment.Specifically,when an obstruction occurs between the sender and receiver,incurring an obstruction for the information transmission.To address the above-mentioed two issues,deploying low-cost and highly flexible Intelligent Reflecting Surface(IRS)can effectively address the reliability issues in agricultural information transmission.This article focuses on formulating a Multiple Input Single Output(MISO)transmission model,using practical finite-alphabet inputs as the research object,and constructing an IRS-aided agricultural information transmission strategy.The main work is summarized as follows:(1)In the scenario that all the transmit antennas convey a same symbol in agricultural wireless networks,a low-complexity transmission algorithm is proposed via jointly designing the base station beamforming and the phase of IRS.Based on the enhanced demand for agricultural information transmission assisted by IRS,considering the coexistence of multiple links between base stations,IRS,and agricultural wireless devices,the receiving strength of base station signals on agricultural wireless devices is enhanced by designing base station transmission beamforming and IRS reflection coefficient,thereby effectively improving the signal-to-noise ratio and optimizing the transmission rate.Finally,the numerical simulation results verify the effectiveness of the design algorithm.(2)For more widely applicable scenario of agricultural information transmission,namely multiple antennas transmitting different symbols,an efficient iteration algorithm is further designed for both the base station active beamforming and IRS phase.By taking the benefit of the cut-off rate,the computational complexity of the objective function was significantly reduced,and an alternating iteration algorithm is invoked to solve the optimization problem of multi-symbol agricultural information transmission rate under the finite-alphabet inputs.For addressing the problem,a pair of standardly convex optimization problems are constructed by using both the Successive Convex Approximation(SCA)technology and the convexity of exponential function.Finally,simulation experiments verify that the proposed alternating iteration optimization algorithm is capable of effectively improving the performance in terms of the transmission rate and reducing the bit-error rate for agricultural information transmissions.