标签: 无线通信链路预算

无线链路预算是一种定量评估通信链路是否会成功执行的计算。它提供了对功率预算的详细分析，说明了传输路径每个阶段的增益和损耗。包含天线架高计算，菲涅尔区半径计算，天线口径计算，自由空间损耗，接收信号电平计算，链路余量，可用度计算等等； 比如在南京地区部署 X 波段高速通信系统，通信距离 10 公里，全双工速率 2Gbps ： link budget 步骤如下： 查阅气象资料得知：南京地区降雨 63mm/h ，年平均气温 15 ℃， 查阅通信站点的经纬度坐标，对天线架设高度高进行计算； 菲涅尔半径计算，确保第一菲涅尔区 60% 可用； 计算接收门限 Threshold= -114+10log(BW)+NF+Eb/No 确定链路余量 fade margin, 计算链路接收电平； 计算链路的系统增益； 计算自由空间链路损耗 Free space path loss =92.4+20log(freq)+20log(distance) 计算天线增益，确定天线口径尺寸； 根据统计信息，计算链路的可用度，比如上述链路通过计算得知：综合考虑多径传输和降雨影响 Multipath + Rain Availability ，其中垂直极化可用度 99.995% ，水平极化可用度 99.992% 验证：上述数据和参数输入 MATLAB 链路预算工具，仿真计算后得到的结果基本与上述计算结果一致。 Ref. Importance of Link Budgets Link budgets are essential for several reasons: 1. System Design : Link budgets guide the design and dimensioning of communication systems, ensuring that the transmitted power, antenna gains, and receiver sensitivity are appropriately chosen for reliable communication. 2. Performance Evaluation : By accounting for all gains and losses, link budgets provide a quantitative assessment of the system’s performance, helping engineers estimate the achievable data rates, coverage range, and signal quality. 3. Regulatory Compliance : Link budgets help ensure compliance with regulatory standards, such as maximum permissible transmit power levels, interference limits, and signal quality requirements.