feature: Estimate CFO from CSI-RS tracking signal

TRS resources if configured by gnb, is present in two consequtive slots
and two symbols per slot. LS estimates from the first symbol is saved
and in second symbol frequency offset and time offset is estimated. The
estimated FO is saved in UE global structure which is used in the last
TRS slot. If the FO is above a threshold, the radio's center frequency
is adjusted.

Time offset is estimated but not used because time is already tracked
using PBCH DMRS.

Signed-off-by: Sakthivel Velumani <s.velumani@northeastern.edu>

nfapi/open-nFAPI/nfapi/public_inc/fapi_nr_ue_interface.h

@@ -463,6 +463,7 @@ typedef struct {
   uint8_t power_control_offset;     // Ratio of PDSCH EPRE to NZP CSI-RSEPRE [3GPP TS 38.214, sec 5.2.2.3.1], Value: 0->23 representing -8 to 15 dB in 1dB steps; 255: L1 is configured with ProfileSSS
   uint8_t power_control_offset_ss;  // Ratio of NZP CSI-RS EPRE to SSB/PBCH block EPRE [3GPP TS 38.214, sec 5.2.2.3.1], Values: 0: -3dB; 1: 0dB; 2: 3dB; 3: 6dB; 255: L1 is configured with ProfileSSS
   uint8_t measurement_bitmap;       // bit 0 RSRP, bit 1 RI, bit 2 LI, bit 3 PMI, bit 4 CQI, bit 5 i1
+  uint8_t last_trs_slot;            // indicates to PHY if the slot is end of TRS burst
 } fapi_nr_dl_config_csirs_pdu_rel15_t;
 
 typedef enum{vrb_to_prb_mapping_non_interleaved = 0, vrb_to_prb_mapping_interleaved = 1} vrb_to_prb_mapping_t;