he number of distinct Cell IDs has been increased to 768 sequences. The length of sequence for the PA- Preamble is 216, regardless of the FFT size. The PA-Preamble carries the information related to system bandwidth and RF carrier configuration, i.e., whether the carrier is fully- (all downlink and uplink 9.13 Synchronization channel IEEE 802.16m W/O CoRe - 1st Transmission IEEE 802.16m CoRe 1st Transmission IEEE 802.16m W/O CoRe 2nd Transmission IEEE 802.16m CoRe 2nd Transmission IEEE 802.16m W/O CoRe 3rd Transmission IEEE 802.16 CoRe 3rd Transmission IEEE 802.16 W/O CoRe 4th Transmission IEEE 802.16m CoRe 4th Transmission SNR (dB) FIGURE 9-56 Performance with and without constellation rearrangement in the downlink [87] control channels are contained) or partially-configured (some of the downlink and uplink control channels are included). The sub-carrier index 256 is reserved for the DC sub-carrier. The sequences of PA-Preamble indices from 3 to 9 in Table 9-11 are reserved for irregular channel bandwidths which support tone dropping. The sub-carriers associated with PA-Preamble are assigned as m = 2k + 41, k = 0, 1, 2, 215. The IEEE 802.16m PA-Preamble is designed in a manner SO as not to degrade the performance of legacy system acquisition. The IEEE 802.16m PA-Preamble enables mobile stations to synchronize in frequency and time without requiring the IEEE 802.16-2009 standard preamble. The IEEE 802.16m PA-Preamble supports timing synchronization by autocorrelation with a repeated waveform. The structure of the PA-Preamble is not identical to that of the legacy preamble in the time-domain, as shown in Figure 9-59. The magnitude boosting levels in single carrier mode for different FFT sizes of 512, 1024, and 2048 are 2.3999, 3.4143, and 5.1320, respectively. As an example, for 512-point FFT, the boosted PA-Preamble at kth sub-carrier is ak = 2.3999 Bk where Bk denotes the kth sub-carrier of the PA-Preamble before boosting. The sub-carrier levels before boosting are +1 or - -1. The SA-Preamble sequences are parti