thgonal code bo,b2... TFCI code (16,5) (5 bits) bi-orthgonal code Figure 4.53 Channel coding of split mode TFCI bits. Table 4.42 Basis Sequences for (16,5) TFCI Code [10] The UTRA Physical Layer Design 4.6.14 Mapping of TFCI Words In non-compressed mode, we map cord word bits directly to the slots of the radio frame, the bit with lower index gets transmitted before the bit with higher index. The coded bits bk, get mapped to the transmitted TFCI bits dk, as follows: dk = bk mod 32. For the UL physical channels, despite the SF and DL physical channels, if the SF 128, = 0,1,2,,..,2916. In like manner, for the DL physical channels whose SF < 128, k = 0, 1,2, 119. The latter implies that bits bo to b23 get transmitted four times and bits b24 to b31 get transmitted three times [10]. In the uplink compressed-mode, we map TFCI bits differently for downlink with SF 128 and downlink with SF < 128. The slot format gets changed SO that we do not lose TFCI bits. We repeat TFCI bits because the different slot formats in compressed mode do not match the exact number of TFCI bits for all possible TGLs. Denoting the number of bits available in the TFCI fields of one compressed radio frame by D and the number of bits in the TFCI field in a slot by NTFCI, we obtain the first bit to get repeated, E = NfirstNTFCI- When Nlast # 14, then E corresponds to the number of the first TFCI bit in the slot directly after the TG. The following expressions define the uplink mapping: dk = bk mod 32 where k = 0,1,2,,..,min(31, D-1). (4.95) If D > 32, the remaining positions get filled in reverse order by repetition: dD-k- b(E+k) mod 32 where k = =0,...,D-33. (4.96) In the downlink compressed mode we change the slot format to prevent TFCI bit losses. When the slot formats do not match the exact number of TFCI bits for all possible TGLs and the number of TFCI fields exceeds the number of TFCI bits we use DTX. The block of fields, where we use DTX starts on the first field after the gap. If fewer TFCI fields exist after the gap than DTX bits, the las