vbsの作法 その22

概要

vbsの作法調べてみた。
AM変調やってみた。

写真

サンプルコード

Dim PI
PI = 3.14159265
Dim SRC(300)
Dim AM(300)
Dim I(300)
Dim Q(300)
Dim I2(300)
Dim Q2(300)
Dim O(300)
Dim csv(300)

For t = 0 to 299
    SRC(t) = Sin(t / 8000 * 2 * PI * 220) * 2 - 1
Next
For t = 0 to 299
    AM(t) = (.6 * Sin(t / 8000 * 2 * PI * 220) + 1) * Sin(t / 8000 * 2 * PI * 3000) * 2 - 1
Next
For t = 0 to 299
    I(t) = AM(t) * Cos(t / 8000 * 2 * PI * 2800)
    Q(t) = AM(t) * Sin(t / 8000 * 2 * PI * 2800)
Next
Q0 = 1
OMEGA = 2 * PI * 300 / 8000
ALPHA = Sin(OMEGA) / (2 * Q0)
A0 = 1 + ALPHA
A1 = -2 * Cos(OMEGA)
A2 = 1 - ALPHA
B0 = (1 - Cos(OMEGA)) / 2
B1 = 1 - Cos(OMEGA)
B2 = (1 - Cos(OMEGA)) / 2
IN1 = 0
IN2 = 0
OUt1 = 0
OUt2 = 0
For t = 0 to 299
    I2(t) = B0 / A0 * I(t) + B1 / A0 * IN1 + B2 / A0 * IN2 - A1 / A0 * OUt1 - A2 / A0 * OUt2
    IN2 = IN1
    IN1 = I(t)
    OUt2 = OUt1
    OUt1 = I2(t)
Next
IN1 = 0
IN2 = 0
OUt1 = 0
OUt2 = 0
For t = 0 to 299
    Q2(t) = B0 / A0 * Q(t) + B1 / A0 * IN1 + B2 / A0 * IN2 - A1 / A0 * OUt1 - A2 / A0 * OUt2
    IN2 = IN1
    IN1 = Q(t)
    OUt2 = OUt1
    OUt1 = Q2(t)
Next
For t = 0 to 299
    O(t) = SQR(I2(t) * I2(t) + Q2(t) * Q2(t)) * 4 - 6
    csv(t) = Cstr(O(t))
Next

Set sh = CreateObject("WScript.Shell")
cd = sh.CurrentDirectory
name2 = cd & "\am2.csv"
msgbox name2
With CreateObject("ADODB.Stream")
    .Type = 2
    .Charset = "Shift_JIS"
    .Open
    .writeText Join(csv, vbCrLf) & vbCrLf
    .saveToFile name2, 2
    .Close
End With

msgbox "ok"

以上。