nized access. The pth ranging preamble code denoted as Xp (k) is defined as follows: k=0,1, NRP - 1 (10-16) where NCS is the unit of cyclic shift according to the cell size, NRP is the length of ranging preamble codes (NRP = 139 for ranging channel Format 0 and NRP =557 for ranging channel Format 1), and P denotes the index of the Pth ranging preamble code, which is constructed by the Bp cyclic-shifted sequence derived from the root index ap of a Zadoff-Chu sequence [2]. The number of cyclic-shifted codes per root index, the start root index of the Zadoff-Chu code, and the ranging preamble code partitioning information are broadcast via a secondary superframe header. The ranging preamble code 2 or 8 * Sequence m th th Sub- 2 or 72 2 or * Sub-carrier Contiguous Band-pass NFFTPoint N Point Sequence Generation Insertion Mapping Sub-carriers Filtering Removal Detection Uplink Subframe Decimation in Frequency Domain FIGURE 10-17 An illustration of the generation and detection of initial ranging sequences CHAPTER 10 The IEEE 802. 16m Physical Layer (Part II) partitioning information indicates the number of initial and handover ranging preamble codes. The transmitted ranging signal waveform as function of time can be expressed as follows: (10-17) In Format 0<1< 2TRP where Noffset is a frequency position adjustment parameter due to the fact that the sub-carrier spacing for a ranging channel is a fraction of the normal sub-carrier spacing. The information regarding ranging channel configuration and allocation is carried through the secondary superframe header. This information includes a subframe offset (OSF) for the ranging channel in the time-domain and the sub- band index for the ranging channel allocation in the frequency-domain, where the latter is determined once the Cell-ID and the number of sub-bands is given. The ranging channel can be scheduled in every frame, in the first frame of every superframe, in the first frame of every even-numbered superframes, and in the first frame of every fourth superframe. Therefor