Common Phase error estimation and compensation in uplink.

FEATURE STATEMENT:
- Introduce linear phase error noise model in Uplink at UE
- Perform common phase error (CPE) estimation and compensation at gNB

SOLUTION:
- A linear phase shift model is introduced in simulation.
- PTRS symbols are used to perform estimation of CPE from DMRS compensated signal
- The estimated values are interpolated in time domain and signal is compensated for the CPE.
- PTRS processing is done in Frequency Domain for each symbol in a slot and
  LLR's are calculated for each symbol accordingly.

IMPLEMENTATION:
* sim.h/channle_sim.c
- Linear Phase Noise Generation model definition.
* nr_ul_channel_estimation.c/nr_ul_estimation.h
- CPE estimation from PTRS and DMRS compensated signal.
* nr_dmrs_rx.c/nr_refsig.h
- Regenerate PTRS symbols at gNB.
* nr_ulsch_demodulation.c
- Removed old PTRS processing code and move to a common PTRS processing function
* defs_gNB.h/init.c
- New PTRS variables definition and initialization
* nr_ulsch_ue.c
- Corrected PTRS parameter to get new PTRS symbols for each OFDM symbol

TESTING
* ulsim.c
- Added Phase noise, Enable PTRS signal and verified the output.

VERIFICATION
- The LLR are rotated back with estimated CPE and no error is observed in scrambling/decoding

cmake_targets/CMakeLists.txt

@@ -2303,6 +2303,7 @@ add_library(LFDS7
 add_library(SIMU_COMMON
   ${OPENAIR1_DIR}/SIMULATION/TOOLS/random_channel.c
   ${OPENAIR1_DIR}/SIMULATION/TOOLS/rangen_double.c
+  ${OPENAIR1_DIR}/SIMULATION/TOOLS/phase_noise.c
   )
 
 # Simulation library

cmake_targets/build_oai

@@ -209,7 +209,7 @@ function main() {
                     GDB=0
                     CMAKE_BUILD_TYPE="RelWithDebInfo"
                     echo_info "Will Compile with gdb symbols"
-                    CMAKE_CMD="$CMAKE_CMD -DCMAKE_BUILD_TYPE=RelWithDebInfo"
+                    CMAKE_CMD="$CMAKE_CMD -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_EXPORT_COMPILE_COMMANDS=1"
                     shift
                     ;;
                 "MinSizeRel")