maki/openairinterface5g
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix dB_fixed() function

Browse Source 
0 in dB is -INF, but since we're dealing with integer variables, we'll put 10*log10(2^-30) in the output, which corresponds to the symmetrical maximum output of the function.
This commit is contained in:
rmagueta
2026-03-04 16:26:59 +00:00
parent 0e38bd239e
commit bc6963c588
2 changed files with 33 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files
openair1/PHY/TOOLS/dB_routines.c
+32 -32
View File
@@ -21,7 +21,7 @@
#include "tools_defs.h"
// Approximate 10*log10(x) in fixed point : x = 0...(2^32)-1
// Approximate 10*log10(x) in fixed point : x = 0...(2^32)-1, where the output is truncated to 10*log10(2^30) = 90 dB
static const int8_t dB_table[256] = {
0, 3, 5, 6, 7, 8, 8, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15,
@@ -131,60 +131,60 @@ int16_t dB_fixed_x10(uint32_t x) {
int16_t dB_fixed_times10(uint32_t x)
{
int16_t dB_power=0;
int16_t dB_power = 0;
if (x==0) {
dB_power = 0;
} else if ( (x&0xff000000) != 0 ) {
dB_power = dB_table_times10[((x>>24)&255)-1];
dB_power += 3*dB_table_times10[255];
} else if ( (x&0x00ff0000) != 0 ) {
dB_power = dB_table_times10[((x>>16)&255)-1];
dB_power += 2*dB_table_times10[255];
} else if ( (x&0x0000ff00) != 0 ) {
dB_power = dB_table_times10[((x>>8)&255)-1];
if (x == 0) {
dB_power = -900; // 0 in dB is -INF, but since we're dealing with integer variables, we'll put 10*log10(2^-30) x 10 in the output
} else if ((x & 0xff000000) != 0) {
dB_power = dB_table_times10[((x >> 24) & 255) - 1];
dB_power += 3 * dB_table_times10[255];
} else if ((x & 0x00ff0000) != 0) {
dB_power = dB_table_times10[((x >> 16) & 255) - 1];
dB_power += 2 * dB_table_times10[255];
} else if ((x & 0x0000ff00) != 0) {
dB_power = dB_table_times10[((x >> 8) & 255) - 1];
dB_power += dB_table_times10[255];
} else {
dB_power = dB_table_times10[(x&255)-1];
dB_power = dB_table_times10[(x & 255) - 1];
}
if (dB_power > 900)
return(900);
return (900);
return dB_power;
}
int8_t dB_fixed(uint32_t x)
{
int8_t dB_power=0;
int8_t dB_power = 0;
if (x==0) {
dB_power = 0;
} else if ( (x&0xff000000) != 0 ) {
dB_power = dB_table[((x>>24)&255)-1];
dB_power += 3*dB_table[255];
} else if ( (x&0x00ff0000) != 0 ) {
dB_power = dB_table[((x>>16)&255)-1];
dB_power += 2*dB_table[255];
} else if ( (x&0x0000ff00) != 0 ) {
dB_power = dB_table[((x>>8)&255)-1];
if (x == 0) {
dB_power = -90; // 0 in dB is -INF, but since we're dealing with integer variables, we'll put 10*log10(2^-30) in the output
} else if ((x & 0xff000000) != 0) {
dB_power = dB_table[((x >> 24) & 255) - 1];
dB_power += 3 * dB_table[255];
} else if ((x & 0x00ff0000) != 0) {
dB_power = dB_table[((x >> 16) & 255) - 1];
dB_power += 2 * dB_table[255];
} else if ((x & 0x0000ff00) != 0) {
dB_power = dB_table[((x >> 8) & 255) - 1];
dB_power += dB_table[255];
} else {
dB_power = dB_table[(x&255)-1];
dB_power = dB_table[(x & 255) - 1];
}
if (dB_power > 90)
return(90);
return (90);
return dB_power;
}
uint8_t dB_fixed64(uint64_t x)
int8_t dB_fixed64(uint64_t x)
{
if ((x<(((uint64_t)1)<<32))) return(dB_fixed((uint32_t)x));
else return(4*dB_table[255]+dB_fixed((uint32_t)(x>>32)));
if ((x < (((uint64_t)1) << 32)))
return (dB_fixed((uint32_t)x));
else
return (4 * dB_table[255] + dB_fixed((uint32_t)(x >> 32)));
}
openair1/PHY/TOOLS/tools_defs.h
+1 -1
View File
@@ -961,7 +961,7 @@ uint32_t angle(struct complex16 perrror);
unsigned char factor2(unsigned int x);
int8_t dB_fixed(uint32_t x);
uint8_t dB_fixed64(uint64_t x);
int8_t dB_fixed64(uint64_t x);
int8_t dB_fixed2(uint32_t x,uint32_t y);
int16_t dB_fixed_times10(uint32_t x);
int16_t dB_fixed_x10(uint32_t x);