UTRA Physical Layer Design We denote the nth Hadamard sequence as a row of H8 numbered from the top, = 0,1, 2, ....,255, in the sequel. In addition, we let hm(i) and z(i) and denote the ith symbol of the sequence hm and Z, respectively where i = 0,1,2,,..,255 and i = 0 corresponds to the leftmost symbol. The ith SCH code word, CSCH,i> i=0,...,15 is then defined as (4.58) where m = (16xi) and the leftmost chip in the sequence corresponds to the chip trans- mitted first in time. This code word gets selected from every 16th row of the matrix H., which yields 16 possible code words. We define the secondary SCH code words in terms of CSCH,i and the definition of {C0,...,C15} now follows as: C = CSCH, i=0,...,15. (4.59) Finally, more details and code allocations and evaluation of synchronization codes can be found in [7]. MULTIPLEXING AND CHANNEL CODING We encode/decode information from/to upper layers to afford transport services over the air interface. Thus, through channel coding we protect data flow by combining error detection and correction and adapting to transmission needs by means of rate matching, interleaving, and mapping of transport channels to physical channels. Multiplexing and channel coding techniques in the UTRA physical layer specifications apply to both FDD and TDD modes in most aspects. Thus, for completeness here we will introduce primarily the description for the FDD because it has more cases (e.g. description for uplink and downlink), and indicate where they differ with the TDD. Specifications in [10] and [18] provide all the details for each mode, respectively. In UTRA data arrives at the coding/multiplexing unit in transport block sets once every transmission time interval. The transmission time interval depends on the transport channel from the set {10 ms, 20 ms, 40 ms, 80 ms}. The main steps valid for both FDD and TDD from [10] are: add CRC to each transport block transport block concatenation and code block segmentation channel coding rate matching insertion of discontinuous transmission (D