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Fix for the ULDLduplex issue for NTN bands

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Duplex is assumed to be static but for NTN bands, it is not static.
TxRX Duplex is defined in section 5.4.4 of 38.101-5 (for NTN) specs v1809
n256 190 MHz, 165 to 215 MHz
n255 -101.5 MHz, -72.5 to -130.5 MHz
n254 862 - 885 MHz
This commit is contained in:
Raghavendra Dinavahi
2025-10-30 15:34:00 +01:00
parent 75a68167ea
commit 69f391f2b8
1 changed files with 29 additions and 2 deletions
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common/utils/nr/nr_common.c
+29 -2
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@@ -459,10 +459,36 @@ bool compare_relative_ul_channel_bw(int nr_band, int scs, int channel_bandwidth,
return rel_bw > limit;
}
static bool check_delta_duplex(int index, uint64_t dlfreq_khz, uint64_t ulfreq_khz)
{
int uldl_min_offset = nr_bandtable[index].dl_min - nr_bandtable[index].ul_min;
int txrx_offset = dlfreq_khz - ulfreq_khz;
LOG_I(NR_PHY, "dlfreq:%ld ulfreq:%ld deltaduplex:%d khz, uldl_min_offset:%d khz\n",
dlfreq_khz, ulfreq_khz, txrx_offset, uldl_min_offset);
if (txrx_offset == uldl_min_offset)
return true;
int band = nr_bandtable[index].band;
// TBD.. Delta duplex is also a range for these bands n26, n91-n94, n109.
// TBD .. Add the checks later
// Refer to section 5.4.4 in spec 38.101-5
if (band == 256 && txrx_offset >= 165000 && txrx_offset <= 215000)
return true;
if (band == 255 && txrx_offset >= -130500 && txrx_offset <= -72500)
return true;
if (band == 254 && txrx_offset >= 862000 && txrx_offset <= 885000)
return true;
return false;
}
uint16_t get_band(uint64_t downlink_frequency, int32_t delta_duplex)
{
const int64_t dl_freq_khz = downlink_frequency / 1000;
const int32_t delta_duplex_khz = delta_duplex / 1000;
const int64_t ul_freq_khz = dl_freq_khz + delta_duplex_khz;
uint64_t center_freq_diff_khz = UINT64_MAX; // 2^64
uint16_t current_band = 0;
@@ -472,9 +498,10 @@ uint16_t get_band(uint64_t downlink_frequency, int32_t delta_duplex)
if (dl_freq_khz < nr_bandtable[ind].dl_min || dl_freq_khz > nr_bandtable[ind].dl_max)
continue;
int32_t current_offset_khz = nr_bandtable[ind].ul_min - nr_bandtable[ind].dl_min;
if (ul_freq_khz < nr_bandtable[ind].ul_min || ul_freq_khz > nr_bandtable[ind].ul_max)
continue;
if (current_offset_khz != delta_duplex_khz)
if (!check_delta_duplex(ind, dl_freq_khz, ul_freq_khz))
continue;
int64_t center_frequency_khz = (nr_bandtable[ind].dl_max + nr_bandtable[ind].dl_min) / 2;