Changes for SIC-receiver:
1. in dlsim.c: now we check for the receiver type and, if SIC, proceed through encoding, modulation, LLR compuattion and decoding of the decoded TB0. 2. Implementing routines for vector-vector multiplication and vector-vector subtraction 3. Adding some printouts for debuging purposes. 4. New functions: modulation_SIC, dlsch_qpsk_llr_SIC 5. In phy_scope.c: changing llr plotting: now for the length of coded_bits_per_cw.