不韋 呂 / Mbed 2 deprecated UIT2_FrequencyShifter

Frequency shifter using analytic signal for ST Nucleo F401RE.

Dependencies:   UITDSP_ADDA mbed

HilbertTransform.hpp@4:04bb0cfea187, 2015-07-25 (annotated)

Committer:
MikamiUitOpen
Date:
Sat Jul 25 07:32:50 2015 +0000
Revision:
4:04bb0cfea187
Parent:
0:4269710caf90 
5

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 0:4269710caf90 1 //--------------------------------------------------------------
MikamiUitOpen 0:4269710caf90 2 // Hilbert transform filter
MikamiUitOpen 0:4269710caf90 3 // Copyright (c) 2014 MIKAMI, Naoki, 2014/06/23
MikamiUitOpen 0:4269710caf90 4 //--------------------------------------------------------------
MikamiUitOpen 0:4269710caf90 5
MikamiUitOpen 0:4269710caf90 6 #ifndef HILBERT_TRANSFORM_HPP
MikamiUitOpen 0:4269710caf90 7 #define HILBERT_TRANSFORM_HPP
MikamiUitOpen 0:4269710caf90 8
MikamiUitOpen 0:4269710caf90 9 #include "mbed.h"
MikamiUitOpen 0:4269710caf90 10
MikamiUitOpen 0:4269710caf90 11 namespace Mikami
MikamiUitOpen 0:4269710caf90 12 {
MikamiUitOpen 0:4269710caf90 13 // order must be 4K+2, K: integer
MikamiUitOpen 0:4269710caf90 14 template<int order> class Hilbert
MikamiUitOpen 0:4269710caf90 15 {
MikamiUitOpen 0:4269710caf90 16 private:
MikamiUitOpen 0:4269710caf90 17 const float *const hm_; // pointer for filter coefficients
MikamiUitOpen 0:4269710caf90 18 float xn_[order+1]; // buffer for inputs
MikamiUitOpen 0:4269710caf90 19
MikamiUitOpen 0:4269710caf90 20 Hilbert(const Hilbert&);
MikamiUitOpen 0:4269710caf90 21 Hilbert& operator=(const Hilbert&);
MikamiUitOpen 0:4269710caf90 22 public:
MikamiUitOpen 0:4269710caf90 23 Hilbert(const float hk[]) : hm_(hk)
MikamiUitOpen 0:4269710caf90 24 {
MikamiUitOpen 0:4269710caf90 25 if ( ((order-2) % 4) != 0)
MikamiUitOpen 0:4269710caf90 26 fprintf(stderr, "order must be 4*K+2, K: integer\r\n");
MikamiUitOpen 0:4269710caf90 27 Clear();
MikamiUitOpen 0:4269710caf90 28 }
MikamiUitOpen 0:4269710caf90 29
MikamiUitOpen 0:4269710caf90 30 // yI: in-phase signal
MikamiUitOpen 0:4269710caf90 31 // yQ: quadrature signal
MikamiUitOpen 0:4269710caf90 32 void Execute(float xin, float& yI, float& yQ)
MikamiUitOpen 0:4269710caf90 33 {
MikamiUitOpen 0:4269710caf90 34 yQ = 0.0;
MikamiUitOpen 0:4269710caf90 35 xn_[0] = xin;
MikamiUitOpen 0:4269710caf90 36
MikamiUitOpen 0:4269710caf90 37 for (int k=0; k<=order/4; k++)
MikamiUitOpen 0:4269710caf90 38 yQ = yQ + hm_[k]*(xn_[2*k] - xn_[order-2*k]);
MikamiUitOpen 0:4269710caf90 39 yI = xn_[order/2]; // in-phase signal
MikamiUitOpen 0:4269710caf90 40
MikamiUitOpen 0:4269710caf90 41 for (int k=order; k>0; k--)
MikamiUitOpen 0:4269710caf90 42 xn_[k] = xn_[k-1]; // move input signals
MikamiUitOpen 0:4269710caf90 43 }
MikamiUitOpen 0:4269710caf90 44
MikamiUitOpen 0:4269710caf90 45 void Clear()
MikamiUitOpen 0:4269710caf90 46 { for (int k=0; k<=order; k++) xn_[k] = 0.0f; }
MikamiUitOpen 0:4269710caf90 47 };
MikamiUitOpen 0:4269710caf90 48 }
MikamiUitOpen 0:4269710caf90 49 #endif // HILBERT_TRANSFORM_HPP
MikamiUitOpen 0:4269710caf90 50
MikamiUitOpen 0:4269710caf90 51