added a new check for illegal file permissions to mbmssim.c, to avoid a segfault if permissions are invalid.

fixed mbmssim compilation issue
one more fix for build script sudo usage

added configuration file for lowband of SoDeRa

changes in lmslib.cpp

removed strage exit in UE receiver

changing LOG_E to LOG_W in rx_pucch_emul when UE is not found (this might happen during attach procedure but is ok since nothing will happen)

small fix for mbmssim (a previous commit enabled XFORMS by default, which was not up to date in mbmssim)

handling of timing advance is improved. MAC retrieves timing advance from phy once prior to DL scheduling and clears the statistic in PHY. A timer for controlling the timing advance periodicity was introduced.

Tested modifications for 23.04 Ms/s 100 PRB transmission/reception (Downlink).  This will reduce I/Q acquisition times for 20 MHz channels.  new option in dlsim (-E) for testing 1536-point DFT instead of 2048 for this lower sampling rate. Added normalization to idft1536.  Should also be added to dft1536 later.

Limitation of non SI DLSCH allocations in subframe 0/5 to PRBS not around DC (avoid puncturing from PBCH). Placement of SI around DC instead of randomized allocations. Placement of RA allocations at PRB 0-3.  Tested DL throughput on 5 MHz to 16 Mbit/s in TM1.