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>