WP 1, D2 – Functional System Parameters description

BROADWAY, IST-2001-32686 WP1-D2 version 1, date 10-10-02 Programme: ISTMobility ofDevicesMobility ofEnvironmentExcess delay tocope withRangeUp to 3 m/sClass A: up to 15 m/sClass B: Up to 15 m/s100-150nsIndoor: 0.5 to 15 metersHL/2, IEEE802.11a assumptionWe should separate the “mobility of devices” and the“mobility of environment”.See section 2.3These parameters will be used for the design of theOFDM parameters.Naturally limited by the wallsDepends on the data rate (see section 2.4)4.2 HIPERSPOT parametersThe following tables contain first values, or range of values, that will be taken as working assumption for theproject. Note that these values are first assumptions, and some of them may change during the project if itturns out that different values would be better.Table 4.2-1: HIPERSPOT system parametersParameter Value CommentsBand59..62 GHzThis band is available worldwideChannelBandwidthsGuardBandwidthbetweenchannels20 MHz … 320 MHzPossibly 40 MHz20 MHz is the HL/2 channel size. For compatibilityreasons, a multiple of 20MHz will be used.The guard band between channels will be large in order toreduce the constraints on the filters. This value is aninitial guess.Table 4.2-2: HIPERSPOT baseband parametersParameter Value CommentsModulationOFDMOFDM is chosen because of its considerable advantagesfor high data rate systems (spectral efficiency, easyequalization, etc.), and for compatibility with existing5GHz WLANs (HL/2, IEEE802.11a) .The 60 GHz channels are expected to have an excessdelay of approx. 100…150 ns. Assuming very shortfilters in the TX/RX, a guard interval size of 200 nsseems to be sufficient (e.g. in the case where only veryGuard Intervalbroad channels are used, the filters become short).50 – 800 nssizeHowever, too short TX/RX filters are expected to lead toperformance drawbacks. In this case, either the guardinterval must be enlarged or means must be provided indigital in order to do some compensation. The 800 nsguard interval might be kept for compatibility reasonswith HL/2.This carrier spacing of 312.5 kHz is used in HL/2. At aCarrier spacing 312.5-2500 kHzfirst guess, this value should be reasonable for 60 GHz,however a phase noise study has to be carried out todetermine if a larger carrier spacing is required.FFT size 64-1024PossibleconstellationsBPSK, QPSK, 16-QAM, 64-QAMThese are the HL/2 constellations. Other constellations(e.g. 8-PSK) may be investigated too.42