如何以编程方式找出载波信号强度 [英] How to find out carrier signal strength programatically

问题描述

以下是我用来查找载波信号强度的代码：

Here is the code that I have used to find out carrier signal strength:

int getSignalStrength()
{
    void *libHandle = dlopen("/System/Library/Frameworks/CoreTelephony.framework/CoreTelephony", RTLD_LAZY);
    int (*CTGetSignalStrength)();
    CTGetSignalStrength = dlsym(libHandle, "CTGetSignalStrength");
    if( CTGetSignalStrength == NULL) NSLog(@"Could not find CTGetSignalStrength");
    int result = CTGetSignalStrength();
    dlclose(libHandle);
    return result;
}

它给我60到100之间的值，但当我测试信号时设备强度通过调用此 * 3001＃12345＃* 数字显示为 -65 。下面我附上了截图。来自 getSignalStrength（）的值是否准确？那为什么它总是返回正值？

It is giving me values between 60 to 100, but when I test the signal strength in device by calling to this *3001#12345#* number it showed me as -65. Below I have attached the screenshot. Is the value coming from getSignalStrength() accurate? Then why is it returning positive values always?

推荐答案

getSignalStrength（）显示否定的dB衰减，例如 - （ - 60）== 60.呼入将更常规地显示为小于零的测量值。是的，这些变化是典型的。即使在严格控制的条件下，您也可以获得+/- 20分贝。解决这个问题的一种方法是随着时间的推移进行一系列测量，比如每秒，并保留最近10次测量的运行列表。然后报告平均值或中位数或其他统计数据。根据我的经验，这会大大减少变化。您也可以使用标准偏差来衡量可靠性。

getSignalStrength() is showing negated dB attenuation, e.g. -(-60) == 60. The call in is displaying it more conventionally as a measurement less than zero. Yes, these kinds of variations are typical. Even in strictly controlled conditions you can get +/- 20 decibels. One way you can fix it is to take a series of measurements over time, say every second, and keep a running list of the last 10 or so measurements. Then report the mean or median or some other statistic. In my experience this cuts down the variation a lot. You can also do standard deviation to provide a measure of reliability.

这篇关于如何以编程方式找出载波信号强度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！