CNG-EbNo SNR Noise Generator
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Data Sheet CNG-EbNo Series Count on the noise leader

CNG-EbNo Series Precision SNR Generators The CNG-EbNo is a fully automated instrument that sets and maintains a highly accurate ratio between a user-supplied carrier and internally generated AWGN noise, over a wide range of signal power levels and frequencies. The CNG-EbNo gives system, design, and test engineers in the cellular/PCS, satellite and military communication industries a cost-effective means of obtaining higher yield through automated testing, plus increased confidence from repeatable, accurate test results. Features Multiple Operating Modes Variable Output Power The CNG-EbNo...

Setting Precision C/N Ratios The CNG-EbNo accurately sets carrier-to-noise ratios using the Eb/No – The instrument automatically sets up a desired Eb/ substitution calibration method. This method eliminates the No quickly and accurately. Based on the user-specified carrier effects of any non-linearity in the measuring device, in this output level, output Eb/No ratio, and bit rate, the instrument case the power meter. This is done by setting the signal and the automatically calculates the required noise density. noise to the same power level at the power meter input. (See the functional...

Carrier to Noise Ratio (C/N) What is it? C/N is the ratio of the relative power level to the noise level in the bandwidth of a system. Why we need it? Allows to analyze if a carrier can still be recognized as such, or if it is obliterated by ambient and system noise. C/N Provides a value for the quality of a communication channel. The quality of the system is usually determined through BER Noise Spectral Density (No) What is No? Noise spectral density (No) is defined as the amount of (white) noise energy per bandwidth unit (Hz). No = N / B No is often expressed as N0 = kT k is the...

Carrier to Noise Density Ratio (C/ No) What is it? C/No is the ratio of the power level to the noise power spectral density (normalized noise level relative to 1 Hz) in a system. Why we need it? Similar as C/N but C/No does not factor the actual noise bandwidth in. This simplifies analysis of systems where variation of the (utilized) BW may apply. As C/N, C/No is usually determined through BER plots Energy per bit (Eb) What is Eb? Energy per information bit (i.e. the energy per bit net of FEC overhead bits). Carrier power divided by actual information bits. R is the actual information bit...

Performance of BER vs Eb/No This block diagram shows an example of typical satellite modem loop test set up from where it is possible to find the ideal performance of BER vs Eb/No. The CNG-EbNo tester sets up the Eb/No and a standard BER test equipment measures the bit error rate. Plotting BER vs. Eb/No produces a waterfall like curve to its shape when plotted in a logarithm graph. Signal Input Eb/No is commonly used with modulation and coding designed Signal+Noise Output for noise-limited rather than interference-limited communica- tion systems, and for power-limited rather than...

Operating modes Carrier-to-noise (C/N), carrier-to-noise density (C/No), bit energyto-noise density (Eb/No), carrier-to-interferer (C/I), noise generator, power meter Carrier Path Input power range Maximum input power Output power range Nominal gain The CNG EbNo offers a variety of advantages over discrete Gain resolution instruments when measuring C/N, C/No , Eb/No or C/I: Gain flatness Group delay Third-order intercept point Tracking update rate CNG EbNo vs. Spectrum Analyzer • Automated procedure, therefore repeatable measurements provided quickly • Highest accuracy through substitution...

Ordering Information Model Number Frequency Range Automatic gain control to maintain constant carrier power level General Purpose General purpose/SATCOM Intelsat, SATCOM Intelsat, SATCOM Covers the same noise specs as HP3708A General Purpose NASA TDRSS Below 800 MHz, standard impedance is 75 Ω. Above 800 MHz, 50 Ω is assumed. In addition to standard TCP/IP Highly recommended for military L-band modems, Satellite IF Loopback Testing Single Band Cellular/PCS 3G Mobile Telecom, CDMA Wireless local loop CNG-EbNo-2442 2400 to 2484 MHz 802.11b Wireless LAN WiFi, Bluetooth CNG-EbNo-2450 Custom...