Change the calculation of UE group A random access preamble selection to choose a random number from [0 nof_groupA_preambles) rather than incrementing on the preambleTransmissionCounter. (#200)

7 years ago · 470953bf9c
parent dfce3ea155
commit 470953bf9c
1 changed files with 5 additions and 3 deletions
--- a/srsue/src/mac/proc_ra.cc
+++ b/srsue/src/mac/proc_ra.cc
@ -237,7 +237,8 @@ void ra_proc::step_resource_selection() {
    }
    if (sel_group == RA_GROUP_A) {
      if (nof_groupA_preambles) {
-        sel_preamble = preambleTransmissionCounter%nof_groupA_preambles;
+        // randomly choose preamble from [0 nof_groupA_preambles)
+        sel_preamble = rand() % nof_groupA_preambles;
      } else {
        rError("Selected group preamble A but nof_groupA_preambles=0\n");
        state = RA_PROBLEM;
@ -245,6 +246,7 @@ void ra_proc::step_resource_selection() {
      }
    } else {
      if (nof_groupB_preambles) {
+        // randomly choose preamble from [nof_groupA_preambles nof_groupB_preambles)
        sel_preamble = nof_groupA_preambles + rand() % nof_groupB_preambles;
      } else {
        rError("Selected group preamble B but nof_groupA_preambles=0\n");