Casper Signal Processing Workshop 2009 SKA Signal Processing (Preliminary) Wallace Turner Domain Specialist for Signal Processing

Download Casper Signal Processing Workshop 2009 SKA Signal Processing (Preliminary) Wallace Turner Domain Specialist for Signal Processing

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<p>Signal Transport and Networks for the SKA Roshene McCool Domain Specialist for Signal Transport and Networks</p> <p>Casper Signal Processing Workshop2009</p> <p>SKA Signal Processing(Preliminary)</p> <p>Wallace TurnerDomain Specialist for Signal ProcessingSPDO1Example Configuration (Phase 2)2 of 35</p> <p>Memo 100 identifies the following options:70-200MHz: Sparse AA200-500MHz: Sparse AA</p> <p>500MHz-10GHz: 3000 15m dishesOr500MHz- 10GHz: 2000 15m dishes with PAFs plus WBSPFOr500MHz-10GHz: 250 Dense AA plus 2400 15m dishes/ WBSPF</p> <p>Note: On going discussions 15m vs 12m dishesExample Configuration with Dense AA + SPFSPDOReference Design3 of 35</p> <p>SPDODishes+Single Pixel Feeds4 of 35</p> <p>American: 6m Hydroformed DishSouth Africa: 15m Composite DishCanadian: 10m Composite DishNote:On going discussions 12m vs. 15m dishRequired sensitivity 10,000 m2K-1Correlator processor and dump rate proportional to Nant2 ADC likely to be at antenna (4 bit ?)O/Prate = fs.4bits = 160 G bits/s per antenna</p> <p>Where fs = sample rate likely to be split into smaller basebandsSPDOAGN Science Chapter Example5 of 35</p> <p>AGN Science ChapterSurvey Speed: 1 x 105 m4K-2deg2Frequency range 500 MHz to 8GHzTsys now: Not achieved over bandwidthTarget Tsys: 35K</p> <p>SPDODishes+Phased Array Feeds6 of 35</p> <p>Apertif Netherlands: Vivaldi ArrayASKAP Australia: Checkerboard ArrayPHAD Canada: Vivaldi ArrayNote:Some Channelization and Beamforming likely to be at antenna.Maximum Field of View limited by Array size and focal length of dish.Achievable field of view limited by network bandwidth.</p> <p>SPDOExample Number PAFs Required7 of 35</p> <p>Wide Field Polarimetry Science ChapterSurvey Speed: 5 x 108 m4K-2deg2Max frequency 2GHz</p> <p>WBSPF would require over 15,000 dishes</p> <p>Tsys now: 100 KTarget Tsys: 50 KSPDOSimplistic View of PAF Processing Consider Frequency Domain BeamformingChannelisation: Nchan ~ 64 12 taps gives &lt; 60db aliasing between channelsProcessing load ~ (Ntaps + 3*log2(Nchan)) x Nel x 2pol x fsNtaps = 12, Nel = 96 x 2pol &amp; fs = 1.4 GHz for 700MHz bandwidthProcessing load= 8 x 1012 MACSBeamformer (per antenna):Average beams per channel 30Processing Load = Nbms.Nel.2pol.fs. 4Multiplies = 3 x 1013 MacsO/Prate= Nbms.2pol.fs.4bits.8B10B = 420 G bit/s42 10 G bit/s optical cables per antennaIncludes 25 % extra bandwidth required for 8B/10B Encoding2000 dishes with PAFs (total 840 T bits/s)Note :*FFT implementation dependent</p> <p>8 of 35SPDOSparse Aperture Arrays9 of 35</p> <p>LOFAR: Netherlands et alLWA: USAMWA: USA &amp; AustraliaNote:Two types of sparse AA required:70MHz 200 MHz200MHz 500 MHz</p> <p>Only solution for EoRHI Science Chapter</p> <p>SPDODense Aperture Array Station10 of 35</p> <p>Assumed Dense Aperture Array~256 tiles x 256 elements per tile2 polarisations per elementSample rate ~ 2.5 G Hz4 bits/ sample56 m diameter250 stations Tsys now 120KTarget 35K Memo 100Processing BunkerDense AA Detail300MHz to 1GHz i.e. 700MHz bandwidthfs=2 x 700 MHz56m diameter array =&gt;2463 m244.4 2pol elements per m^2 (30 cm wavelength) = 110,000 elements x 2pol per station, about 2 x 64k elements.Array efficiency 80%, Bore efficiency 75%&amp; Tsys = 35K -&gt; 250 stations for 10,000m2K-1 sensitivitySPDOSimplistic View of Dense Aperture Array ProcessingConsider Frequency Domain BeamformingDelay is implemented as a phase slope in frequency domain.Alternative time domain with tuned lengths of co-ax.Channelisation: Nchan 1024, 12 taps gives &lt; 60db aliasing between channelsNtaps = 12, Nant = 64k x 2pol &amp; fs = 1.4 GHz for 700MHz bandwidthProcessing ~ (Ntaps + 3*log2(Nchan)) x Nant x 2pol x fs**=8 x 1015 MACSBeamformer (per station):Average 1437 beams per channel to cover 250 sq degrees FoVProcessing Load = Nant.2pol.Nbms.fs. 4MACS = 1 x 1018 MACSO/Prate**= Nbms.2 pol.fs.4bits.8B10B = 20 T bit/sOver 2000 10 G bit/s optical cables, 8B/10B Encoding factor 1.25Up to 250 Dense AA Stations (total 10 peta bits/s)Note :*FFT implementation dependent **Ignores upsampling of channelizer</p> <p>11 of 35SPDOCorrelator Processing LoadsChannelisation (700MHz bandwidth):SPF 4 x 1014 (105 channels)PAF 4 x 1012 (4096 fine channels giving ~ 105 total)Dense AA 6 x 1015 (128 fine channels ~ 105 total)Correlation load (700 MHz bandwidth)SPF load = 6 x 1016 MACSPAF load = 1 x 1018 MACSDense AA = 2 x 1018 MACSCorrelator Dump Rate (Dish Solution) 2280 15 m dishes + 40 x 18 dish stations and 3000 km baseline:Integration time ~ 200ms for &lt; 1% smearing5 x 106/2 baselines x 105 channels x 4 bytes x 5 Hz = 9 T Bytes/sNot calculated for other configurations yet</p> <p>12 of 35SPDOSignal Processing Overview Memo 100 Option a*13* Sparse AAs + 3000 15-m dishes with SPFs</p> <p>SPDO13Signal Processing OverviewMemo 100 option b*14 of 35* Sparse AAs + 2400 15-m dishes with PAFS &amp; WBSPF</p> <p>Possibly include a beam former for the coreSPDOSignal Processing OverviewMemo 100 option c*15 of 35* Sparse AAs + 250 Dense AA + 2000 15-m dishes with SPFs</p> <p>SPDOTechnology OptionsFPGAVirtex 6 (available 2010): 2016 x DSP slices clocked at 600 MHz -&gt; 1200 G MACS~ 25 G MACs per Watt1018 MACS requires ~ 106 FPGAS =&gt; 48 W per device and ~ 48 M Watts for 1018 MACS Operating cost 1$ per Watt per year =&gt; $48M per annumPlus cost of cooling and delivering powerASIC22nm (available 2010): 2.5 nW/MHz/Gate &gt; 40 T MACS (4 bit) per device =&gt; 25,000 devices Assuming &lt; 50 % gates switching at any one time: 600kWOperating cost $600k per annum </p> <p>16 of 35</p> <p>SPDOWhat would F or X unit look like?</p> <p>17 of 35</p> <p>Baseline Board (front)Station Board Baseline Board (rear)Pictures courtesy Brent CarlsonEVLA style boards might be an optiton ?64 ASICS or FPGAs on board (~1.5 kW card)~ 190 boards for Dense AA ASIC correlator14 cards per shelf -&gt; 14 shelvesIs production yield an issue? Could use smaller 8 processor chip board As per ASKAP or UniboardInter-board Communication links increase</p> <p>SPDOMultichip Module18 of 35</p> <p>SKADS have developed a promising Multichip Module:4 x 4 antenna array currently,Current RFI Protection shows -57dB per M (in air)Picture courtesy of Kris Zarb AdamiCould be developed and used in several areas of the SKA(Note that the key components are ADC and Optical I/O, although the others could be useful in some applications.)</p> <p>SPDOCorrelator Centre Build Cost19 of 35Kevin Wohlever 2006ASIC solution1 cabinet per 30 sq ftBetween 80 &amp; 160 cabs?Factor of 4 for air con &amp;PSU units, offices~ 50 W per sq ft</p> <p>SPDOSPDO TeamProject DirectorRichard SchilizziProject Engineer Peter Dewdney Executive OfficerColin GreenwoodProject ScientistJoe LazioSystem EngineerKobus Cloete Domain Specialist Receptors Neil Roddis Domain Specialist Signal TransportRoshene McCool Domain Specialist Computing &amp; SoftwareDuncan Hall Domain Specialist Signal ProcessingWallace TurnerSite EngineerRob Millenaar Project Management OfficerBilly AdamsIndustry Relations ManagerPhil CrosbyOffice ManagerLisa Bell</p> <p>20SPDO20</p>