Skip to content

firdes: Make fractional delay consistent #198

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
fsheikh wants to merge 1 commit into
base: master
Choose a base branch
from
Open

firdes: Make fractional delay consistent #198

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 6 additions & 6 deletions include/liquid.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2068,16 +2068,16 @@ void liquid_firdes_gmsktx(unsigned int _k, unsigned int _m, float _beta, float _
void liquid_firdes_gmskrx(unsigned int _k, unsigned int _m, float _beta, float _dt, float * _h);

// Design flipped exponential Nyquist/root-Nyquist filters
void liquid_firdes_fexp( unsigned int _k, unsigned int _m, float _beta, float _dt, float * _h);
void liquid_firdes_rfexp(unsigned int _k, unsigned int _m, float _beta, float _dt, float * _h);
void liquid_firdes_fexp( unsigned int _k, unsigned int _m, float _beta, float * _h);
void liquid_firdes_rfexp(unsigned int _k, unsigned int _m, float _beta, float * _h);

// Design flipped hyperbolic secand Nyquist/root-Nyquist filters
void liquid_firdes_fsech( unsigned int _k, unsigned int _m, float _beta, float _dt, float * _h);
void liquid_firdes_rfsech(unsigned int _k, unsigned int _m, float _beta, float _dt, float * _h);
void liquid_firdes_fsech( unsigned int _k, unsigned int _m, float _beta, float * _h);
void liquid_firdes_rfsech(unsigned int _k, unsigned int _m, float _beta, float * _h);

// Design flipped arc-hyperbolic secand Nyquist/root-Nyquist filters
void liquid_firdes_farcsech( unsigned int _k, unsigned int _m, float _beta, float _dt, float * _h);
void liquid_firdes_rfarcsech(unsigned int _k, unsigned int _m, float _beta, float _dt, float * _h);
void liquid_firdes_farcsech( unsigned int _k, unsigned int _m, float _beta, float * _h);
void liquid_firdes_rfarcsech(unsigned int _k, unsigned int _m, float _beta, float * _h);

// Compute group delay for an FIR filter
// _h : filter coefficients array
Expand Down
1 change: 0 additions & 1 deletion include/liquid.internal.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -957,7 +957,6 @@ void liquid_firdes_fnyquist(liquid_firfilt_type _type,
unsigned int _k,
unsigned int _m,
float _beta,
float _dt,
float * _h);

// flipped exponential frequency response
Expand Down
12 changes: 6 additions & 6 deletions src/filter/src/firdes.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -376,13 +376,13 @@ void liquid_firdes_prototype(liquid_firfilt_type _type,
liquid_firdes_rcos(_k, _m, _beta, _dt, _h);
break;
case LIQUID_FIRFILT_FEXP:
liquid_firdes_fexp(_k, _m, _beta, _dt, _h);
liquid_firdes_fexp(_k, _m, _beta, _h);
break;
case LIQUID_FIRFILT_FSECH:
liquid_firdes_fsech(_k, _m, _beta, _dt, _h);
liquid_firdes_fsech(_k, _m, _beta, _h);
break;
case LIQUID_FIRFILT_FARCSECH:
liquid_firdes_farcsech(_k, _m, _beta, _dt, _h);
liquid_firdes_farcsech(_k, _m, _beta, _h);
break;

// root-Nyquist filter prototypes
Expand All @@ -406,13 +406,13 @@ void liquid_firdes_prototype(liquid_firfilt_type _type,
liquid_firdes_gmskrx(_k, _m, _beta, _dt, _h);
break;
case LIQUID_FIRFILT_RFEXP:
liquid_firdes_rfexp(_k, _m, _beta, _dt, _h);
liquid_firdes_rfexp(_k, _m, _beta, _h);
break;
case LIQUID_FIRFILT_RFSECH:
liquid_firdes_rfsech(_k, _m, _beta, _dt, _h);
liquid_firdes_rfsech(_k, _m, _beta, _h);
break;
case LIQUID_FIRFILT_RFARCSECH:
liquid_firdes_rfarcsech(_k, _m, _beta, _dt, _h);
liquid_firdes_rfarcsech(_k, _m, _beta, _h);
break;
default:
fprintf(stderr,"error: liquid_firdes_prototype(), invalid root-Nyquist filter type '%d'\n", _type);
Expand Down
26 changes: 6 additions & 20 deletions src/filter/src/fnyquist.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -41,14 +41,12 @@
// _k : samples/symbol
// _m : symbol delay
// _beta : rolloff factor (0 < beta <= 1)
// _dt : fractional sample delay
// _h : output coefficient buffer (length: 2*k*m+1)
void liquid_firdes_fnyquist(liquid_firfilt_type _type,
int _root,
unsigned int _k,
unsigned int _m,
float _beta,
float _dt,
float * _h)
{
// validate input
Expand Down Expand Up @@ -105,32 +103,28 @@ void liquid_firdes_fnyquist(liquid_firfilt_type _type,
// _k : samples/symbol
// _m : symbol delay
// _beta : rolloff factor (0 < beta <= 1)
// _dt : fractional sample delay
// _h : output coefficient buffer (length: 2*k*m+1)
void liquid_firdes_fexp(unsigned int _k,
unsigned int _m,
float _beta,
float _dt,
float * _h)
{
// compute resonse using generic function
liquid_firdes_fnyquist(LIQUID_FIRFILT_FEXP, 0, _k, _m, _beta, _dt, _h);
liquid_firdes_fnyquist(LIQUID_FIRFILT_FEXP, 0, _k, _m, _beta, _h);
}

// Design fexp square-root Nyquist filter
// _k : samples/symbol
// _m : symbol delay
// _beta : rolloff factor (0 < beta <= 1)
// _dt : fractional sample delay
// _h : output coefficient buffer (length: 2*k*m+1)
void liquid_firdes_rfexp(unsigned int _k,
unsigned int _m,
float _beta,
float _dt,
float * _h)
{
// compute resonse using generic function
liquid_firdes_fnyquist(LIQUID_FIRFILT_FEXP, 1, _k, _m, _beta, _dt, _h);
liquid_firdes_fnyquist(LIQUID_FIRFILT_FEXP, 1, _k, _m, _beta, _h);
}

// flipped exponential frequency response
Expand Down Expand Up @@ -181,32 +175,28 @@ void liquid_firdes_fexp_freqresponse(unsigned int _k,
// _k : samples/symbol
// _m : symbol delay
// _beta : rolloff factor (0 < beta <= 1)
// _dt : fractional sample delay
// _h : output coefficient buffer (length: 2*k*m+1)
void liquid_firdes_fsech(unsigned int _k,
unsigned int _m,
float _beta,
float _dt,
float * _h)
{
// compute resonse using generic function
liquid_firdes_fnyquist(LIQUID_FIRFILT_FSECH, 0, _k, _m, _beta, _dt, _h);
liquid_firdes_fnyquist(LIQUID_FIRFILT_FSECH, 0, _k, _m, _beta, _h);
}

// Design fsech square-root Nyquist filter
// _k : samples/symbol
// _m : symbol delay
// _beta : rolloff factor (0 < beta <= 1)
// _dt : fractional sample delay
// _h : output coefficient buffer (length: 2*k*m+1)
void liquid_firdes_rfsech(unsigned int _k,
unsigned int _m,
float _beta,
float _dt,
float * _h)
{
// compute resonse using generic function
liquid_firdes_fnyquist(LIQUID_FIRFILT_FSECH, 1, _k, _m, _beta, _dt, _h);
liquid_firdes_fnyquist(LIQUID_FIRFILT_FSECH, 1, _k, _m, _beta, _h);
}

// flipped exponential frequency response
Expand Down Expand Up @@ -257,32 +247,28 @@ void liquid_firdes_fsech_freqresponse(unsigned int _k,
// _k : samples/symbol
// _m : symbol delay
// _beta : rolloff factor (0 < beta <= 1)
// _dt : fractional sample delay
// _h : output coefficient buffer (length: 2*k*m+1)
void liquid_firdes_farcsech(unsigned int _k,
unsigned int _m,
float _beta,
float _dt,
float * _h)
{
// compute resonse using generic function
liquid_firdes_fnyquist(LIQUID_FIRFILT_FARCSECH, 0, _k, _m, _beta, _dt, _h);
liquid_firdes_fnyquist(LIQUID_FIRFILT_FARCSECH, 0, _k, _m, _beta, _h);
}

// Design farcsech square-root Nyquist filter
// _k : samples/symbol
// _m : symbol delay
// _beta : rolloff factor (0 < beta <= 1)
// _dt : fractional sample delay
// _h : output coefficient buffer (length: 2*k*m+1)
void liquid_firdes_rfarcsech(unsigned int _k,
unsigned int _m,
float _beta,
float _dt,
float * _h)
{
// compute resonse using generic function
liquid_firdes_fnyquist(LIQUID_FIRFILT_FARCSECH, 1, _k, _m, _beta, _dt, _h);
liquid_firdes_fnyquist(LIQUID_FIRFILT_FARCSECH, 1, _k, _m, _beta, _h);
}

// hyperbolic arc-secant
Expand Down
3 changes: 3 additions & 0 deletions src/filter/src/rcos.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,9 @@ void liquid_firdes_rcos(unsigned int _k,
} else if ( (_beta < 0.0f) || (_beta > 1.0f) ) {
fprintf(stderr,"error: liquid_firdes_rcos(): beta must be in [0,1]\n");
exit(1);
} else if ( (_dt < -0.5f) || (_dt > 0.5f) ) {
fprintf(stderr, "error: liquid_firdes_rcos(): fractional delay must be in [-0.5, 0.5]\n");
exit(1);
} else;

unsigned int n;
Expand Down
3 changes: 3 additions & 0 deletions src/filter/src/rrcos.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,9 @@ void liquid_firdes_rrcos(unsigned int _k,
} else if ( (_beta < 0.0f) || (_beta > 1.0f) ) {
fprintf(stderr,"error: liquid_firdes_rrcos(): beta must be in [0,1]\n");
exit(1);
} else if ( (_dt < -0.5f) || (_dt > 0.5f) ) {
fprintf(stderr, "error: liquid_firdes_rrcos(): fractional delay must be in [-0.5, 0.5]\n");
exit(1);
} else;

unsigned int n;
Expand Down