不韋 呂 / Mbed 2 deprecated SDR_AM_Rx_CIC

AM中波放送用SDR．CICフィルタのみを使用．CQ出版社「トランジスタ技術」誌，2021年4月号に掲載

Dependencies:   mbed

SDR_Library/QuadOscIir.hpp@2:4bec6b2be809, 2020-08-29 (annotated)

Committer:
MikamiUitOpen
Date:
Sat Aug 29 11:19:03 2020 +0000
Revision:
2:4bec6b2be809
Parent:
1:30d9fb51dec1 
3

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 0:6906f8616429 1 //--------------------------------------------------------------
MikamiUitOpen 2:4bec6b2be809 2 // IIR フィルタを利用する直交信号発生器のクラス
MikamiUitOpen 0:6906f8616429 3 //
MikamiUitOpen 2:4bec6b2be809 4 // 2020/07/30, Copyright (c) 2020 MIKAMI, Naoki
MikamiUitOpen 0:6906f8616429 5 //--------------------------------------------------------------
MikamiUitOpen 0:6906f8616429 6
MikamiUitOpen 0:6906f8616429 7 #include "mbed.h"
MikamiUitOpen 0:6906f8616429 8
MikamiUitOpen 0:6906f8616429 9 #ifndef QUAD_PHASE_OSC_IIR_HPP
MikamiUitOpen 0:6906f8616429 10 #define QUAD_PHASE_OSC_IIR_HPP
MikamiUitOpen 0:6906f8616429 11
MikamiUitOpen 0:6906f8616429 12 namespace Mikami
MikamiUitOpen 0:6906f8616429 13 {
MikamiUitOpen 0:6906f8616429 14 class QuadOscIir
MikamiUitOpen 0:6906f8616429 15 {
MikamiUitOpen 0:6906f8616429 16 public:
MikamiUitOpen 0:6906f8616429 17 // コンストラクタ
MikamiUitOpen 2:4bec6b2be809 18 // f0 周波数，単位：Hz
MikamiUitOpen 2:4bec6b2be809 19 // ts 標本化間隔，単位：μs
MikamiUitOpen 2:4bec6b2be809 20 // amp 振幅
MikamiUitOpen 0:6906f8616429 21 QuadOscIir(float f0, float ts, float amp = 1)
MikamiUitOpen 0:6906f8616429 22 : TS_(ts*1.0E-6f), A0_(amp) { Set(f0); }
MikamiUitOpen 0:6906f8616429 23
MikamiUitOpen 2:4bec6b2be809 24 // sin/cos 発生
MikamiUitOpen 0:6906f8616429 25 void Generate(float &sinX, float &cosX)
MikamiUitOpen 0:6906f8616429 26 {
MikamiUitOpen 2:4bec6b2be809 27 float vn = a1_*vn1_ - vn2_;
MikamiUitOpen 2:4bec6b2be809 28 sinX = b1S_*vn1_;
MikamiUitOpen 2:4bec6b2be809 29 cosX = A0_*vn + b1C_*vn1_;
MikamiUitOpen 0:6906f8616429 30
MikamiUitOpen 2:4bec6b2be809 31 vn2_ = vn1_; // v[n-2] ← v[n-1]
MikamiUitOpen 2:4bec6b2be809 32 vn1_ = vn; // v[n-1] ← v[n]
MikamiUitOpen 0:6906f8616429 33 }
MikamiUitOpen 0:6906f8616429 34
MikamiUitOpen 0:6906f8616429 35 // 出力周波数の設定，周波数を変更し再スタートする場合も使える
MikamiUitOpen 0:6906f8616429 36 // f0：周波数，単位：Hz
MikamiUitOpen 0:6906f8616429 37 void Set(float f0)
MikamiUitOpen 0:6906f8616429 38 {
MikamiUitOpen 2:4bec6b2be809 39 static const float PI2 = 6.283185f;
MikamiUitOpen 2:4bec6b2be809 40 a1_ = 2.0f*cosf(PI2*f0*TS_);
MikamiUitOpen 2:4bec6b2be809 41 b1S_ = A0_*sinf(PI2*f0*TS_);
MikamiUitOpen 2:4bec6b2be809 42 b1C_ = -A0_*cosf(PI2*f0*TS_);
MikamiUitOpen 2:4bec6b2be809 43 vn1_ = 1.0f;
MikamiUitOpen 2:4bec6b2be809 44 vn2_ = 0.0f;
MikamiUitOpen 0:6906f8616429 45 }
MikamiUitOpen 0:6906f8616429 46
MikamiUitOpen 0:6906f8616429 47 private:
MikamiUitOpen 0:6906f8616429 48 const float TS_; // 標本化間隔
MikamiUitOpen 0:6906f8616429 49 const float A0_; // 振幅
MikamiUitOpen 0:6906f8616429 50 float a1_, b1S_, b1C_;
MikamiUitOpen 2:4bec6b2be809 51 float vn1_, vn2_;
MikamiUitOpen 0:6906f8616429 52
MikamiUitOpen 2:4bec6b2be809 53 // コピー･コンストラクタ，代入演算子の禁止のため
MikamiUitOpen 2:4bec6b2be809 54 QuadOscIir(const QuadOscIir&);
MikamiUitOpen 2:4bec6b2be809 55 QuadOscIir& operator=(const QuadOscIir&);
MikamiUitOpen 0:6906f8616429 56 };
MikamiUitOpen 0:6906f8616429 57 }
MikamiUitOpen 2:4bec6b2be809 58 #endif // QUAD_PHASE_OSC_IIR_HPP