1 DCPRS CERTIFICATION STANDARD STATUS DCS MANUFACTURERS MEETING MAY 18, 2006 Peter Woolner Mitretek Systems

2 Status of Original Items as of May 2006 ITEM NAME Agreement Date Agreement Result CS Paragraph Comments ATiming AccuracyAug S2.1 BMessage FormatAug-04Reword3.1FSS, preamble, new code CData ScramblingMar-04Reword3.2No requirement change DEncoder FlushMar-0432 bits3.4Added definition of "OFF" EInterleaverAug-04DeleteNANot useful FProhibited CharactersAug-04DeleteNARedundant GEOTAug-04Binary only3.6.2Not required for other modes HMaximum Message LengthAug-04To Fail-safe4.6See item Q below ITransmit Frequency AdjustmentAug-04DeleteNANo longer needed JRF Power OutputAug-0448/51 +/ NEW QUESTIONS KOperating FrequenciesNov-05New Plan4.2.1Use center half of old channel LLong Term Frequency StabilityAug Hz4.2.2NEW QUESTION MModulator StabilityAug-04DeleteNACombined with item N NPhase NoiseNONEOPEN4.4NOT RESOLVED ONarrow Band Transmit SpectrumNov-0525/35 dB4.5Meet NTIA requirement PMid-Band Transmit SpectrumNov Log(P)4.5Meet NTIA requirement QFail-SafeAug-0432/128 k4.6Near 110 seconds RDCPI LinkAug-04DeleteNAMake separate document STest NotesNONEOPENApp. ASUGGESTIONS REQUIRED

3 CS Progress Since 11/05 Prepared and distributed a draft CS –New Emission Designators (Para 1.2) –Specified New FSS (Para 3.1) –Proposed Phase Noise (Para 4.4 +) –Added Transmit Spectral Masks (Para 4.5) Confirmed this is Normal NTIA Procedure but using narrower measurement bandwidth –Created Table of Frequencies (App. D)

4 Summary of Stellar Filter Study Results The Study showed there was very little difference in the performance of the Bessel and the Root Raised Cosine (RRC) filters if both are 8th order or higher. Sidelobes at -25 dB down from carrier were set by SSPA distortion and were largely independent of filter type. The RRC filter had somewhat less implementation loss than Bessel filters but required more back-off to meet sidelobe requirements. Both differences were close to the accuracy limit of the simulation. Both types of filter can easily support the proposed reduced channel spacing of 750 Hz. Most unexpected result was the RRC filter performance remains good as filter reduced to fourth order, but the Bessel filter requires at least eighth order to meet the sidelobe requirements. This fact was considered a good reason to recommend use of fourth order RRC filters with 65 coefficients (plus ISI performance).

5 Application of Filter Results NOAA will require RRC filters at WCDAS Strongly recommend all other receive systems require the same type filters Proposed WCDAS filter requirements: –RRC* for 150 and 600 sps –Excess bandwidth = 1.0* –Fourth order with 65 taps or more (*: currently listed in section 4.5 of C.S.) Are other public specifications necessary?

6 NTIA Mask, Doppler, and Frequency Tolerance for 300 bps 225 Hz + 25 Hz Hz = 375 Hz

7 NTIA Mask, Doppler, and Frequency Tolerance for 1200 bps 900 Hz + 25 Hz Hz = 1125 Hz

8 NTIA Mask, Doppler, and Frequency Tolerance (Concluded) Summary: –Reference is peak of MODULATED waveform –Need 25 Hz for Doppler due to trend for large inclination on GOES satellites –1200 bps links will regrow sidebands sooner than 300 bps links as they use higher power Recommendation: –Frequency tolerance up to 125 Hz for both 300 and 1200 bps is OK if vendors want it

9 CHAN 1 CHAN 3 CHAN 5 CHAN 2 CHAN 4 CHAN 7 CHAN 6 CHAN 9 CHAN 8 CHAN 11 CHAN bps Channels OLD 1.5 KHZ CHAN 1 OLD 1.5 KHZ CHAN 2 OLD 1.5 KHZ CHAN 3 OLD 1.5 KHZ CHAN 4 OLD 1.5 KHZ CHAN 5 Low Pilot CHAN OLD 1.5 KHZ CHAN 6 FREQUENCY PLAN #1 EVEN NUMBERED (RED) CHANNELS ON EAST SATELLITE ODD NUMBERED (BLUE) CHANNELS ON WEST SATELLITE

10 OLD 1.5 KHZ CHAN 15 OLD 1.5 KHZ CHAN 12 OLD 1.5 KHZ CHAN 13 OLD 1.5 KHZ CHAN 14 Proposed Transition Process OLD 1.5 KHZ CHAN 11 OLD 1.5 KHZ CHAN 12 OLD 1.5 KHZ CHAN 13 OLD 1.5 KHZ CHAN 15 OLD 1.5 KHZ CHAN 16 11E 21 12E 23 13E 25 11W 22 12W 24 14E 27 13W 26 15E 29 14W 28 16E 31 15W 30 16W 32 OLD 1.5 KHZ CHAN 14 OLD 1.5 KHZ CHAN 11 OLD 1.5 KHZ CHAN 12 OLD 1.5 KHZ CHAN 15 OLD 1.5 KHZ CHAN 16 11E 21 12E 23 13E 25 11W 22 12W 24 14E 27 13W 26 15E 29 14W 28 16E 31 15W 30 16W 32 OLD 1.5 KHZ CHAN 13 OLD 1.5 KHZ CHAN 14 OLD 1.5 KHZ CHAN 11 OLD 1.5 KHZ CHAN 16 11E 21 12E 23 13E 25 11W 22 12W 24 14E 27 13W 26 15E 29 14W 28 16E 31 15W 30 16W 32 ASSUMES THERE ARE NO 100 BPS USERS ON NEARBY CHANNELS (Red channels on GOES East, blue channels on GOES West) STEP 1 STEP 2 STEP 3

11 Old and New 300 bps Adjacent

12 Phase Noise Requirement Current proposed C.S. requirements are –Bias or offset = 1.0 degree –Total RMS phase error due to all causes except bias = 2.5 degrees Produces a total of 3.5 degrees RMS for the complete DCPR path Produces a BER contribution of due to total phase noise

13 Phase Noise Calculation for DCPR Angular limit to produce errors in 8PSK = 45/222.5degrees Source of Phase Noise Contribution Allocation (degrees) Single Meas'mt Satellite Transponder1.0 Wallops Receive Path2.0 DCPR Receiver1.0 DCPR Transmitter RSS Total x*σ for 10E-9/E-6 BER6.1 Sigma * RSS Total Offset/Bias Limit W/C Phase Noise

14 Possible EIRP Reduction Every user would benefit if all uplink power levels were reduced – However: All calculations must be compatible with NOAA defined “worst case” loading –205 uplinks at 48.5 dBmi EIRP Include satellite NPR (16 dB on GOES-P) Work into DRGS with G/T = 15 dB/K If 300 bps reduced by 5 dB to 44 – 42 dBmi and 1200 bps reduced by 2 dB to 50 – 48 dBmi, the estimated E B /N 0 for each is 12.7 dB

15 How Can EIRP be Reduced? Requires ability to adjust power on site (a) Gradual reduction of transmitters with highest EIRP, a few at a time –Requires many years cooperation by all users (b) DCPI Power Control for all DCPRS –Short term DCPI costs –Power cost benefits only in long term Low EIRP design only useable after required powers have been reduced

16 Test Measurements Transmit spectrum –With random modulation, sweep with 1 Hz resolution bandwidth, averaging allowed –Compare peak level with sidelobe levels Phase noise –Measure several thousand symbols using a random data stream and a Vector Signal Analyzer to give average and RMS jitter for each point on the modulation constellation

17 Prime Power Current C. S. section 4.0 requires operation over ±15% from nominal voltage New proposal to allow the manufacturer to specify any desired range –Also proposes the transmission be inhibited if the range is exceeded I suggest add to Fail-Safe as third item –Performance unknown if limits exceeded –Ultimate step to prevent harm to other users

18 Other Suggestions Antenna Labeling –Require a label to identify approved antennas Output Power minimum –Change to -2 dB from nominal is suggested –300: 49 to 44, 1200: 52 to 50 is possible Carrier phase noise –Change to 1.25 degrees for carrier jitter Pilot Policy –Current frequencies and MHz – is 250 Hz below Ch. 200 center – would be 250 Hz below Ch. 400 center