Post on 13-Mar-2018
Jens Medler, October 20071 The CISPR-RMS Detector –A new CISPR weighting detector
Jens Medler, October 20072 The CISPR-RMS Detector –A new CISPR weighting detector
Overview� Principles and definition for the weighting of radio disturbances
� Detectors and alternative methods for the weighting of disturbances:� Peak, Quasi-peak, RMS and Average detector� Distinction between narrowband and broadband disturbances
� Investigation of CISPR-RMS weighting characteristic:� Methods for the determination of the weighting function by a radio system� Mathematical investigations� Numerous measurement results
� Construction and properties of the CISPR-RMS detector
� Consequences for the measurement of typical disturbances
� Conclusion
Jens Medler, October 20073 The CISPR-RMS Detector –A new CISPR weighting detector
Motivation for weightingSituation after installation of AM radio (from 1922):
� Numerous complaints from sound broadcast listeners
� Other electrical devices and apparatus were already existing before AM radiointroduced
� Subsequent disturbance suppression was unavoidable
� Compromise between user and manufacturer of devices
� Minimizing the cost of disturbance suppression, while keeping an agreed level ofradio protection
� First standards were instruction guides for disturbance suppression
� Measurement methods were not developed at that time; later on disturbancevoltage measurement method; CISPR was founded in 1933
� The first CISPR measuring receiver in 1939 was already equipped with a Quasi-peak detector = Simulation of radio receiver plus listener
Jens Medler, October 20074 The CISPR-RMS Detector –A new CISPR weighting detector
Rationale for Quasi-peak detectorTo a listener the degradation of reception quality, caused by a 100-Hz pulse,is equivalent to the degradation from a 10-Hz pulse, if the pulse level isincreased by an amount of 10 dB.
Jens Medler, October 20075 The CISPR-RMS Detector –A new CISPR weighting detector
Definition of weightingWeighting (e.g. of impulsive disturbance) =
The pulse-repetition-frequency (PRF) dependent conversion (mostlyreduction) of a peak-detected impulse voltage level to an indication whichcorresponds to the interference effect on radio reception
� For the analog receiver, the psychophysical annoyance of the interferenceeffect is a subjective quantity (acoustic or visual, usually it cannot bemeasured in figures)
� For the digital receiver, the interference effect may be defined by thecritical Bit Error Ratio (BER) or Bit Error Probability (BEP), for whichperfect error correction can still occur or by another objective andreproducible parameter
Jens Medler, October 20076 The CISPR-RMS Detector –A new CISPR weighting detector
Definition of weighting� Weighting characteristic: The peak voltage level = f(fp) for a constant
effect on a specific radio communication system, i.e. the disturbance isweighted by the radio communication system itself
� Weighting function or weighting curve: The relationship between inputpeak voltage level and PRF for constant level indication of a measuringreceiver with a weighting detector, i.e. the curve of response of a measuringreceiver to repeated pulses
� Weighting factor: The value in dB of the weighting function relative to areference PRF or relative to the peak value
� Weighting detector: A detector which provides an agreed weightingfunction
� Weighted disturbance measurement: Measurement of disturbance usinga weighting detector
Jens Medler, October 20077 The CISPR-RMS Detector –A new CISPR weighting detector
Detectors and alternative methods of weightingWeighting functions of Peak, Quasi-peak, RMS and Average detector:
Comparison of detector weighting functions(example for Bands C and D with 120 kHz bandwidth)
0
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1 10 100 1000 10000 100000 1000000
fp/Hz
WeightingFactor/dB Average
RMSQuasi-PeakPeak
Jens Medler, October 20078 The CISPR-RMS Detector –A new CISPR weighting detector
Detectors and alternative methods of weightingDistinction between narrowband and broadband disturbances(requires unique definition)� Narrowband disturbances causing strong whistle noises on AM receivers,
for that reason lower limits are necessary for narrowband disturbance
Distinction method:� Comparison of Average and Peak values
� Comparison of Peak values by using different bandwidths
� Tuning method (+/-1 bandwidth)
� Different limit values for QP and Average
Jens Medler, October 20079 The CISPR-RMS Detector –A new CISPR weighting detector
Detectors and alternative methods of weighting
Comparison of linear and log. Average Detectors
0,0
20,0
40,0
60,0
80,0
100,0
120,0
0,1 1 10 100 1000 10000 100000 1000000 10000000
PRF/Hz
Mea
s. v
alue
/dB
uV
400 ns/log.AV400 ns/lin.AV1 ms/lin.AV1 ms/log.AV
400 ns/lin. Av.
400ns/log. Av.
1 ms/lin.Av.
1
1 ms/log.Av
Particular sharp suppression of impulsive disturbance: log AV
Jens Medler, October 200710 The CISPR-RMS Detector –A new CISPR weighting detector
Projects to weighting characteristicsWeighting characteristicis influenced by modulation and coding methods as well aserror correction procedures
Digital Modulation - Fundamental Properties:
� Coding Method – by adding of „tail bits“ and „data frames“,„convolution coding“ and „interleaving“� Redundancy for error detection and correction
� Different modulation methods GMSK, QPSK, OFDM, QAM and adaptedmethods
� Data compression and preprocessing
� BER limitation for each System for perfect reception
� Projects in CISPR/A and ITU-R
Jens Medler, October 200711 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
Radio SignalGenerator
BER
InterferenceSource
RadioReceiver
Principle investigation method by using measurement instrumentwith BER meter (e.g. communication analyzer)
Simulation of weighting function
InterferenceSource
MeasuringReceiver
Jens Medler, October 200712 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
Att 0 dB*
CLRWR
B
*1 PK
*RBW 9 kHzVBW 30 kHzSWT 3.1 sRef 90 dBµV
Center 128 MHz Span 50 MHz5 MHz/
PRN
-10
0
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60
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80
90
1
Marker 1 [T1 ]61.89 dBµV
128.000000000 MHz
Pulse Width 0,2 µs Pulse Repetition Freq. <10 kHz
Interference Signal Type 1: Pulse modulated carrier
Jens Medler, October 200713 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
A
Att 10 dBRef -20 dBm
Center 500 MHz Span 20 MHz2 MHz/
* RBW 30 kHzVBW 100 kHzSWT 25 ms
2 PKVIEW
1 PKVIEW
PRN
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
1
Marker 1 [T1 ]-36.37 dBm
500.160000000 MHz
Date: 11.AUG.2004 17:11:24
Interference Signal Type 2: Pulse signal with QPSK modulation
Jens Medler, October 200714 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
Arrangement in CISPR frequency bands:
� CISPR Band A (9 k – 150 kHz):� no digital radio services at the moment
� CISPR Band B (0,15 – 30 MHz):� DRM (Digital Radio Mondial)
� CISPR Band C/D (30 – 1000 MHz):� DVB-T, DAB, TETRA, GSM 900, FM
� CISPR Band E (1 – 18 GHz):� GSM 1800, DECT, IS-95, J-STD 008, CDMA2000, W-CDMA
Jens Medler, October 200715 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristicsBand B: DRM (Digital Radio Mondial), Interference Signal Type 1
DRM at 5,975 MHz; 6,095 MHz; 6,140 MHz; 7,320 MHz; 13,605 MHz;data rate 20,9 kBit/s; signal level kept at constant SNR
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1 10 100 1000 10000f p / Hz
dB µ Vwidth 1E-05s
width 5E-05s
width 1E-04s
width 5E-04s
corner frequencyabout 5 Hz
Jens Medler, October 200716 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristicsBand B: DRM (Digital Radio Mondial), Interference Signal Type 2
DRM Mode B 16/64QAM prot. level 0: Trend
0 dBµV
20 dBµV
40 dBµV
60 dBµV
80 dBµV
100 dBµV
120 dBµV
140 dBµV
1 Hz 10 Hz 100 Hz 1000 Hz 10000 Hz
pulse repetition frequency
puls
e le
vel (
Pk)
200 ns1 µs
10 µs100 µs
1 m s10 m s
corner frequencyabout 100 Hz
Jens Medler, October 200717 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
DVB-T f = 500 MHz, 64 QAM 8k, CR 3/4, GI 1/8, BER before RS = 2.10-4, -61,7 dBm, 24,88 Mbit/s(ES)
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140
1 10 100 1.000 10.000 100.000 1.000.000 10.000.000
fp/Hz
dBuV
width 0,1E-06swidth 0,2E-06swidth 0,5E-06swidth 1,0E-06width 2,0E-06width 5,0E-06swidth 10E-06
Band C/D: DVB-T in Spain, Interference Signal Type 1
corner frequency>1000 Hz
Jens Medler, October 200718 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristicsBand C/D: DVB-T with 64-QAM, Interference Signal Type 2
DVB-T 8k 64QAM 2/3: Trend
0 dBµV
20 dBµV
40 dBµV
60 dBµV
80 dBµV
100 dBµV
120 dBµV
10 Hz 100 Hz 1000 Hz 10000 Hz 100000 Hz
pulse repetition frequency
puls
e le
vel (
Pk)
50 ns
200 ns
0.5 µs
1 µs5 µs
10 µs
corner frequencyabout 1 kHz
Jens Medler, October 200719 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
DAB (QPSK 2/3): Trend
0 dBµV
20 dBµV
40 dBµV
60 dBµV
80 dBµV
100 dBµV
120 dBµV
10 Hz 100 Hz 1000 Hz 10000 Hz 100000 Hz
pulse repetition frequency
puls
e le
vel (
Pk)
50 ns200 ns
0.5 µs1 µs
5 µs10 µs
Band C/D: DAB (Digital Audio Broadcasting), OFDM,Interference Signal Type 2
corner frequencyabout 5 kHz
Jens Medler, October 200720 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
TETRA downlink f = 394,0 MHz, BER = 2%
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10 100 1000 10000 100000 1000000 10000000
f / Hz
dB(µV)width 0,1E-06swidth 0,5E-06swidth 1,0E-06swidth 5,0E-06swidth 10,0E-06s
Band C/D: TETRA, narrowband system, π/4-DQPSK,Interference Signal Type 1
corner frequencyabout 500 Hz
Jens Medler, October 200721 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
GSM 900 Type 1 downlink f = 947,4MHz RBER 1b = 0,4% 400 frames -90 dBm
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120
100 1000 10000 100000 1000000 10000000
f / Hz
dBµVwidth 0,1E-06swidth 0,5E-06swidth 1,0E-06swidth 2,0E-06swidth 5,0E-06swidth 10,0E-06s
corner frequencyabout 2 kHz
Band C/D: GSM 900, GMSK modulation with TDMA,Interference Signal Type 1, RBER1 and RBER2 are used
Jens Medler, October 200722 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
C/I Improvement for τ = 10 µs
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100 1000 10000 100000f/Hz
dB
BERFERRBER 1bRBER 2
corner frequencyabout 1,5 kHz
Band C/D: GSM 900, arithmetic simulation with COSSAP (Neibig/Bosch)RBER1 and RBER2 are used
Jens Medler, October 200723 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
10−3
10−2
10−1
100
101
0
20
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60
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100
120
Normalized Pulse Repetition Frequency
Pea
k va
lue
for
cons
tant
BE
P [d
BV
]UncodedConv. R=2/3, K=3Conv. R=1/2, K=3Conv. R=1/4, K=3
Band C/D: Arithmetic simulation by Stenumgaard (Sweden)BPSK modulation with convolution coding similar to DVB-TR = Code Rate, K = number of shift register steps
corner frequencywith high
redundancy
corner frequencywith low
redundancy
Jens Medler, October 200724 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
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100 1000 10000 100000
QP
RMS
2 µs pulses
Pulse repetition frequency / Hz
Pul
se le
vel [
dBµV
]
Band C/D: FM (analogue modulation; keeps on air beyond 2010)Disturbance level measured with RMS and QP for constant S/NInterference Signal Type 2
Jens Medler, October 200725 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristicsBand E: DECT, ADPCM (Adaptive Differential PCM) GMSKInterference Signal Type 1
DECT FP f = 1897,344MHz, BER = 2 %, Evaluation Time = 5,0s
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100 1000 10000 100000 1000000 10000000f /Hz
dB(µV)
width 0,1E-06swidth 0,5E-06swidth 1,0E-06swidth 2,0E-06swidth 5,0E-06swidth 10,0E-06s
corner frequencyabout 50 kHz
Jens Medler, October 200726 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
IS-95 forward f = 878,49 MHz, FER = 2%, -83 dBm, full rate
0
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120
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100 1000 10000 100000 1000000 10000000
f / Hz
dB(µV)width 0,1E-06swidth 0,5E-06swidth 1,0E-06swidth 2,0E-06swidth 5,0E-06swidth 10,0E-06s
Band E: CDMA with QPSK modulation (IS-95 and J-STD 008)Interference Signal Type 1
corner frequency2 kHz
Jens Medler, October 200727 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
CDM A2 0 0 0 f or wa r d f = 19 5 5 M Hz ; FER = 0 , 5 %; da t a r a t e 9 ,6 k Bi t / s; signa l l e v e l - 112 dBm
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100 1000 10000 100000 1000000f / Hz
dB µVwidth0,1E-06s
width0,2E-06s
width0,5E-06s
width1,0E-06s
width2,0E-06s
Band E: 3G system CDMA2000 with low data rateInterference Signal Type 1
corner frequencyabout 20 to 50 kHz
Jens Medler, October 200728 The CISPR-RMS Detector –A new CISPR weighting detector
Investigation of weighting characteristics
CDM A2 00 0 f or wa r d f = 19 55 , 0 M Hz ; FER = 0 , 5%; di f f e r e nt da t a r a t e s; si gna l l e ve l - 106 dBm;pul se wi dt h 0 , 1 us
0
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100 1000 10000 100000 1000000f / Hz
dB µV
datar ate9,6kB/ s
dater ate76,8kB/ s
Band E: CDMA2000 comparison with low and high data rateInterference Signal Type 1
corner frequency isgoing down to about 10 kHzwith high data rate
Jens Medler, October 200729 The CISPR-RMS Detector –A new CISPR weighting detector
Evaluation of weighting characteristics
data rate 76,8 kb/s; above fc, curves are very close to rms109CDMA2000
data rate 9,6 kb/s; above fc, curves are very close to rms509CDMA2000
very similar to IS-95; above fc close to rms59J-STD 008
very similar to J-STD 008; above fc close to rms29IS-95
above fc flatter than rms509DECT
above fc very close to rms1,57, 8, 9GSM 1800
weighting characteristics follows rms down to 0,5 kHz< 0,5(2) unpubl.FM
above fc very close to rms1,57, 8, 9GSM 900
narrowband system, mainly used below 1 GHz0,59TETRA
fc partially depending on wp52, 9DAB
fc depending on wp, modulation and coding0,1 - 102, 11DVB-T
10 Hz chosen for feasibility0,1/0,0052, 10DRM
Commentfc in kHzReferenceSystem
Determination of corner frequency between RMS and AF detectionBand A und B: 10 Hz; Band C/D: 100 Hz; Band E: 1000 Hz
Jens Medler, October 200730 The CISPR-RMS Detector –A new CISPR weighting detector
Construction – CISPR-RMS Detector
RMS+Average weighting functions for Bands A, B, C/D and E
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1 10 100 1000 10000 100000 1000000
fp/Hz
WeightingFactor/dB RMS-AV Bands C/D
RMS-AV Band ERMS-AV Band ARMS-AV Band B
Measurement bandwidth:Band A: 200 Hz, Band B: 9 kHz, Band C/D: 120 kHz, Band E: 1 MHzWeighting functions for the shortest possible pulse width
Jens Medler, October 200731 The CISPR-RMS Detector –A new CISPR weighting detector
Construction – CISPR-RMS Detector1. RMS detector that continuously determines r.m.s. values
during periods of time equal to the reciprocal of the cornerfrequency fc(example: 1 ms for Band E with corner frequency = 1kHz)
2. Followed by a linear Average detector with meter time constant
3. Moving coil-instrument for Average detection with meter timeconstant has unsteady indication if fp < 5 Hz
4. Peak reading takes the maximum of the alternating value
RMSdetector
linearaveragedetector
Peakreading
with meter timeconstant
Jens Medler, October 200732 The CISPR-RMS Detector –A new CISPR weighting detector
Consequences for measurement of typ. disturbances
RMS+Average weighting detector compared to existing detectors(example as proposed for Bands C and D)
10 dB/decadecorner frequency
20 dB/decade
RMS-AV
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1 10 100 1000 10000 100000 1000000
fp/Hz
WeightingFactor/dB Average
RMS-AVQuasi-PeakPeak
The weighting function of the CISPR-RMS detector lies in betweenAverage und Quasi-Peak detector (example Band C/D)
Jens Medler, October 200733 The CISPR-RMS Detector –A new CISPR weighting detector
Consequences for measurement of typ. disturbances
+22,04+3,9218,90116Washing machine 2
+9,22+1,7126,980,71Washing machine 2
+19,91+3,8013,68124Washing machine 1
+21,79+4,7420,670,768Washing machine 1
+26,84+8,4933,8035Hairdryer
+11,81+3,3932,751,0Hairdryer
Quasi-peakminus Average
in dB
RMS-Averageminus Average
in dB
Average valuein dB(µV)
fin MHz
EUT
There is a realistic hope to have only one limit value for one detector in the future.Limit values for the RMS-Average detector may about 4 dB above the currentlimits for Average detection.
Jens Medler, October 200734 The CISPR-RMS Detector –A new CISPR weighting detector
Standardization Update – CISPR-RMS DetectorAfter long development (start in 1991):
� Background material to weighting detector measurements has beenpublished in Amendment 2:2006 to CISPR 16-3:2003
� Specification of RMS-average measuring receiver has been publishedin Amendment 2:2007 to CISPR 16-1-1:2006(replaces the existing RMS measuring receiver)
� Round Robin Test in CISPR/I/WG1 to CISPR 13 took place,Round Robin Test in CISPR/I/WG2 to CISPR 32 took place
� Topic of new working project in CISPR/I (CISPR/I/232/CD):Draft CISPR 13 A3 Ed.4: “Introduction of the RMS-average detectoras an alternative to quasi-peak and average detector limits“� CD has been confirmed, next stage CDV (Committee Draft for Vote)
Jens Medler, October 200735 The CISPR-RMS Detector –A new CISPR weighting detector
Standardization Update – CISPR-RMS Detector
“The majority of interference shows itself in the form of repeated impulses.The early work of the CISPR led to the conclusion that the best measure ofthe effect of this type of interference would be made by apparatus employinga quasi-peak type of voltmeter. Subsequent experience has shown that anr.m.s. voltmeter might give a more accurate assessment but the quasi-peak detector has been retained for the following reasons:(1) the variation of indication with prf agrees reasonably well with that of anr.m.s. meter ... within the audio-frequency range(2) extensive practical experience ... over a period of many years with the qptype of instrument(3) a large number of interference measuring sets employing this type ofvoltmeter .. in existence”
The RMS Detector was already under discussion when CISPR 1 waspublished in 1972, the introductory note states:
Nowadays the majority of disturbance sources may not contain repeatedpulses, but still a great deal of equipment contains broadband emissions(with repeated pulses) and pulse-modulated narrowband emissions.
Jens Medler, October 200736 The CISPR-RMS Detector –A new CISPR weighting detector
ConclusionIf the CISPR-RMS detector will be accepted by CISPR a longdevelopment process ends
� The new detector may� replace Quasi-Peak and Average detectors in the frequency range
below 1 GHz� have a more appropriate weighting in the range above 1 GHz
� Speed up measurements� A long measurement time is not necessary for the majority of
measurements (similar to Average detector)� Instrument time constant for pulse repetition frequencies < 10 Hz� further experience are necessary
� Application also for spurious emissions reasonable
Jens Medler, October 200737 The CISPR-RMS Detector –A new CISPR weighting detector
Thank you for your attention !