Multi-Carrier and Spread Spectrum Systems: From OFDM and MC ...

260 ApplicationsSub-carriers (frequency)n0132652n+1OFDM symbols (time)n+2002 154 175252n+130 132652Fixed location pilot Variable location pilot DataFigure 5-37Sub-carrier allocation in the uplinkTable 5-22OFDMA uplink sub-carrier allocationParameterValueNumber of DC sub-carriers 1Number of guard sub-carriers, left/right 176/175Number of used sub-carriers 1696Total number of sub-carriers 2048Number of sub-channels 32Number of data sub-carriers per sub-channel 48Number of pilot sub-carriers per sub-channel 5parameters of S-OFDMA with a guard interval of 1/8 are listed in Table 5-24. Channelbandwidths from 1.25 MHz up to 20 MHz are supported. The sampling frequency isproportional to the selected bandwidth. The number of OFDMA sub-channels increasesas the bandwidth increases, leading to a better exploitation of frequency diversity.In Table 5-25 the sub-channel allocation parameters in the case of 5 ms frame durationfor 5 and 10 MHz channel allocations are given. Note that S-OFDMA supports subchannelizationin both DL and UL. The minimum frequency–time resource unit of subchannelizationis one slot, which is equal to 48 data tones (sub-carriers).