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Introduction to Real-Time Spectrum Analysis.

Introduction to Real-Time Spectrum Analysis. Gary Swinton RTSA Product Specialist UK. TRIGGER. CAPTURE. ANALYZE. Agenda. Overview of Real Time Spectrum Analysis Concepts Current Spectrum Analysis challenges What is Real Time Spectrum Analysis Real Time Spectrum Analysis Capabilities

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Introduction to Real-Time Spectrum Analysis.

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  1. Introduction to Real-Time Spectrum Analysis. Gary Swinton RTSA Product Specialist UK TRIGGER CAPTURE ANALYZE Intro to RTSA

  2. Agenda • Overview of Real Time Spectrum Analysis Concepts • Current Spectrum Analysis challenges • What is Real Time Spectrum Analysis • Real Time Spectrum Analysis Capabilities • Unique Triggering • Seamless Capture • Powerful Analysis • Applications and Demo • Overview of Tektronix Real Time Spectrum Analyser family. • Q&A Intro to RTSA

  3. Technology Trends in RF Wireless is everywhere Accelerating shift to Digital RF, fully leveraging computer technologies RF prevalent across a broad range of industries Crowded RF spectrum Increased surveillance and intelligence gathering Intro to RTSA

  4. The world of RF today….. • The growth is in “Digital RF” • Consumer, commercial, military … • Digital devices with RF interfaces • DSP replacing analog signal processing • RF signals are more complex • Precisely timed bursts • Frequency hopping • Spectral and modulation changes over time • Limited Spectrum availability. • Existing tools are not adequate • SA and VSA have limitations, a new solution is required • The time dimension can no longer be ignored • Need to identify transient and random events. Intro to RTSA

  5. Evolution of Signal Analysis Techniques SA VSA RTSA 1960s 1990s TODAY MarketDrivers • Military • Communication systems • Emerging solid state technology • Encryption • Military signal intelligence • Cell phones • Complex digital modulation • Congested RF spectrum • Pervasiveness of low cost RF in consumer electronics • Growth of DSP-based, modulation-agile communication systems Measurement Challenges • High frequency measurements • Analog modulation • Digital Demodulation • Emergence of Standards • Time-varying, bursted, and transient RF signals • Complexity of wireless communication standards Solutions • RF power vs. frequency • Low noise floor • High dynamic range • Digital modulation analysis • Flexible time-correlated multi-domain analysis • Seamless capture of RF signals changing over time • Frequency domain trigger Intro to RTSA

  6. Why Current Solutions Aren’t Adequate SA Short-Comings • Limited digital modulation analysis • No frequency change over time • No frequency domain triggering • Swept acquisition • No memory • Single domain views VSA Short-Comings • Poor Spectrum Analyzer performance • Limited dynamic range • Controls and human interface unfamiliar to SA users • No frequency domain trigger • Misses transient events • No analysis reference to time. • No multi domain correlated views. Intro to RTSA

  7. Intro to Real-time Spectrum AnalysisTime-correlated Multi-domain Analysis • Analyze RF signals simultaneously in three domains: • Time • Frequency • Modulation • Use the flexible analysis windows to select and zoom in on the desired portion of the captured signal Intro to RTSA

  8. Time-correlated Multi-domain Analysis Time vs. Power view Frequency vs. Power view Time-correlated multi-domain display Error vector measurements Constellation view Intro to RTSA

  9. Local Oscillator Traditional Swept Architecture Input Display Resolution Bandpass Filter Time Sweep Intro to RTSA

  10. Real-time Architecture Intro to RTSA

  11. TIME Swept vs. Real-time Seamless Capture Swept Analyzers Real-Time Analyzers FREQUENCY FREQUENCY Intro to RTSA

  12. on an RF signal based on power or frequency characteristics the signal seamlessly in time, into memory the signal simultaneously in multiple domains Time Domain Frequency Domain Modulation Domain Real-time Spectrum Analysis Trigger | Capture | Analyze | Intro to RTSA

  13. Real Time Spectrum Analyzer ConceptsThe Real Time Spectrum Analyzer Process Trigger on any event Capture the Signal seamlessly, frame by frame, into Memory Frame 1 Frame 2 Frame 3 Frame 4 Frame N Signal is stored into memory Analyze the Frequency Domain over time – FFT produces frequency domain Intro to RTSA

  14. Time Frame n Frame 1 Frame 2 Frame 3 Frame 4 Basic Operation of RTSA (1)How does a user capture X seconds of data? • Use TIMING menu to set acquisition length to X seconds • RTSA captures X seconds of signal information in a single block • Block consists of “n” frames, each with 1024 samples • The frames are captured and stored into memory one at a time • No gaps between the frames 1024 Samples per frame (fixed) Time to Acquire 1 Frame = Frame Acquisition Time Time to acquire 1 block (n frames) = acquisition length Intro to RTSA

  15. Frame 1 Frame 2 Frame 3 Frame 4 Frame n Spectrum 4 Spectrum n Spectrum 3 Spectrum 2 Spectrum 1 Basic Operation of RTSA (2)Turning Time into Frequency • RTSA performs FFT on each individual frame resulting in “n” spectra • These “n” spectra represent a seamless history of the frequency domain characteristics Intro to RTSA

  16. DDC Trigger ADC Real Time Spectrum Analyzer ConceptsReal-Time Spectrum Analyzer Block Diagram • Down convert Input signal • Digitize input signal • IF signal is down converted, filtered & detected by DSP in the DDC. • Time to Frequency domain transformation by FFT RF Input Signal IF Signal I RF Memory Converter Q Processor Local Oscillator Sample Clock User Interface Intro to RTSA

  17. 2 LVDS ports that provide digital I and Q data coming directly from the signal path. Streaming is independent of block length (no limit to length of seamless capture). The customer must provide hardware to capture, store and process the IQ data. DDC Trigger ADC New RTSA Capability: Streaming IQ Output IQ Output RF Input Signal IF Signal I RF Memory Converter Q Processor Local Oscillator Sample Clock User Interface Intro to RTSA

  18. Wider capture bandwidth Frequency domain effects Sample rate increases RBW increases Freq resolution decreases Time domain effects Time resolution increases Frame length decreases Max record length decreases Narrower capture bandwidth Frequency domain effects Sample rate decreases RBW decreases Freq resolution increases Time domain effects Time resolution decreases Frame length increases Max record length increases Frequency/Time Tradeoffs Capture Narrow Span Wide span Intro to RTSA

  19. Capture bandwidth = 15 MHz Frequency domain effects Sample rate = 25.6 Msps NBW = 43.7 kHz Freq resolution = 25.0 kHz Time domain effects Time resolution = 39.0 nsec Frame length = 40.0 usec Max record length = 2.56 sec(for RSA3300A w/Opt 02 - 256 MB RAM) Capture bandwidth = 1 kHz Frequency domain effects Sample rate = 1.6 ksps NBW = 2.67 Hz Freq resolution 1.56 Hz Time domain effects Time resolution = 625 usec Frame length = 640 msec Max record length = 11.4 hours(for RSA3300A w/Opt 02 - 256 MB RAM) Frequency/Time Tradeoff Example Capture 1 kHz 15 MHz Intro to RTSA

  20. Span (Hz) Frame time Time Resolution Frequency Resolution Number of bins In span 15M 40us 39.0625ns 25kHz 600 10M 80us 78.125ns 12.5kHz 800 5M 160us 156.25ns 6.25kHz 800 2M 320us 312.5ns 3.125kHz 640 1M 640us 625ns 1.5625kHz 640 500k 1.28ms 1.25us 781.25Hz 640 200k 3.2ms 3.125us 312.5Hz 640 100k 6.4ms 6.25us 156.25Hz 640 50k 12.8ms 12.5us 78.125Hz 640 20k 32ms 31.25us 31.25Hz 640 10k 64ms 62.5us 15.625Hz 640 5k 128ms 125us 7.8125Hz 640 2k 320ms 312.5us 3.125Hz 640 1k 640ms 625us 1.5625Hz 640 500 1.28s 1.25ms 781.25mHz 640 200 3.2s 3.125ms 312.5mHz 640 100 6.4s 6.25ms 156.25mHz 640 Relationship of span, frame time and resolution **RSA3308A** Intro to RTSA

  21. Improved Time Resolution of the RSA3408A Intro to RTSA

  22. Frequency Mask Trigger • Define a frequency mask which can be used to trigger on specific events in the frequency domain • Reliably detect and capture elusive RF signals that a level trigger cannot see in a crowded spectral environment Intro to RTSA

  23. Seamless Capture and Spectrogram • The spectrogram shows how an RF signal changes over time in the frequency domain • Frequency is the horizontal axis, time is the vertical axis, and power is represented by the color of the trace Intro to RTSA

  24. Trigger on any change in the monitored spectrum Seamlessly captureand store a span of RF frequencies at once Analyze how the frequency and amplitude changes over time Real Time Spectrum Analyzer ConceptsThe Real Time Spectrum Analyzer Advantage Intro to RTSA

  25. Real Time Spectrum Analysis Capabilities Analysis - Practical Examples • Spectrogram shows frequency domain behavior over time with amplitude • Spectrum view shows an instantaneous spectrum at the selected moment of time • Analyzer Settings: • Span 5 MHz • Acquisition length 16ms • Spectrum frame time 160s • Measuring Pulsed/Burst Signal Intro to RTSA

  26. Real Time Spectrum Analysis Capabilities Analysis - Practical Examples Intro to RTSA

  27. Enabling Engineers to View Signal Instabilities and Transients that They Never Knew Existed. Meeting RF Measurement Challenges With: • Enhanced Triggering • More Capture Bandwidth • New Analysis Tools Real-Time Spectrum Analyzer A Dramatic Advance Intro to RTSA

  28. RTSA Family RSA2200A RSA3300A WCA200A RSA3400A Trigger Level Frequency mask, Power & Level Frequency mask,Power & Level Frequency mask,Power & Level Capture 10MHz Real-Time BW 15MHz Real-Time BW 15MHz Real-Time BW 36MHz Real-Time BW -73dBc 3rd Order Dynamic Range -74dBc 3rd Order Dynamic Range -74dBc 3rd Order Dynamic Range -78dBc 3rd Order Dynamic Range Analyze Time, Frequency, Analog Modulation Time, Frequency, Analog & Digital Modulation Time, Frequency, Analog & Digital Modulation, 2-3G Time, Frequency, Analog & Digital Modulation, 2-3G, WLAN, Pulse Intro to RTSA

  29. Frequency Mask 36 MHz bandwidth Power Trigger 36 MHz bandwidth 36 MHz real-time capture bandwidth and modulation analysis bandwidth Digital IQ Output 421 MHz IF Output Dynamic range of 66 dB ACLR -78 dBc 3rd Order IM (4dB Improvement) Removable HDD 20nsec resolution Spectrogram using overlap FFT processing Pulsed signal characterization suite New Demodulation - 2ASK and 2FSK, 128 QAM, OQPSK Built-in WLAN 802.11a/b/g analysis New Capabilities of the RSA3408A Trigger Capture Analyze Intro to RTSA

  30. New RTSA Capability: Overlapping FFTs Signal Captured in the Time Domain Acquired Signal Data Transformed into FFT Frames, No Overlap Processing 1024 Samples 1024 Samples 1024 Samples 1024 Samples 1024 Samples 1024 Samples Acquired Signal, Post-Processed with Overlap FFTs 1024 Samples 1024 Samples 1024 Samples FFT Overlap Samples 1024 Samples Overlap Interval Samples 1024 Samples 1024 Samples Intro to RTSA

  31. Overlapping FFT Intro to RTSA

  32. Overlapping FFT continued Intro to RTSA

  33. Overlapping FFTs – “Zoom” for the Spectrogram • Top spectrogram shows no overlap, same as the WCA200A/RSA3300A • Frame Resolution = 40us • 768 FFT points overlap (FFT interval – 256 points) • Frame resolution = 10us • 960 FFT points overlap (FFT interval – 64 points) • Frame resolution = 2.5us • Frame resolution can be set to 20ns • 40 or 36 MHz span • A 2000x improvement over existing 40us Intro to RTSA

  34. Without overlapping FFTs With overlapping FFTs Zooming into the Spectrogram display Chirped Radar Intro to RTSA

  35. 2 LVDS ports that provide digital I and Q data coming directly from the signal path. Streaming is independent of block length (no limit to length of seamless capture). The customer must provide hardware to capture, store and process the IQ data. DDC Trigger ADC New RTSA Capability: Streaming IQ Output IQ Output RF Input Signal IF Signal I RF Memory Converter Q Processor Local Oscillator Sample Clock User Interface Intro to RTSA

  36. RSA3408A APPLICATION EXAMPLESRadar and Pulsed Signals Time vs. Power or Delta Power View Trend of p-p Phase Across All Pulses Individual Pulses Can Be Characterized Intro to RTSA

  37. Real-Time Spectrum Analysis:A New Approach for Measuring Time-varying RF Signals • Trigger on dynamic RF signals • Identify discrete events in the time or the frequency domain • Capture RF signals into memory • Acquire seamless time record ofan entire span of RF frequencies • Analyze RF signals completely • Make correlated time, frequency, and modulation domain measurements Intro to RTSA

  38. Agenda • Overview of Real Time Spectrum Analysis Concepts • Current Spectrum Analysis challenges • What is Real Time Spectrum Analysis • Real Time Spectrum Analysis Capabilities • Unique Triggering • Seamless Capture • Powerful Analysis • Applications and Demo • Q&A Intro to RTSA

  39. Real Time Spectrum Analysis Capabilities Triggering • Flexible Triggers to capture any signal • Level • Power BW • Frequency Mask Trigger • External Trigger - Trigger IN and Trigger OUT • 3 Modes to maximize how the signal is captured • Free Run • Continuous • Single • Position the Trigger anywhere • Enables Pre &/or Post Trigger analysis Intro to RTSA

  40. Real Time Spectrum Analysis Capabilities Triggering • Four Real-time Trigger Modes • Level Trigger (Full BW) • Trigger on all events within the fixed IF bandwidth of the analyzer that exceed the selected threshold. Same as “IF level trigger” on a swept analyzer. (Standard) • Power Trigger (Span BW) • Trigger on all events within the selected span of the analyzer that exceed the selected threshold. (Option 02) • Frequency Mask Trigger • Trigger on discrete frequency domain events based on a flexible user-defined trigger mask. (Option 02) • External Trigger • Trigger on external TTL signals via TRIG IN. (Standard) Intro to RTSA

  41. Real Time Spectrum Analysis Capabilities Frequency Mask Trigger • Trigger and Capture any individual frequency event • Spurious Signals • Transient Signals • Frequency changes • Amplitude Changes • Define the spectrum that has to monitored • Graphically trace out the frequencies that need to be monitored • Define the change • Are you looking for the signal to increase or decrease in amplitude Intro to RTSA

  42. Real Time Spectrum Analysis Capabilities Applications for Frequency Mask Trigger • Interference hunting • Trigger on signals that are buried in crowded spectrum • Spectrum Monitoring • Detect signals that try to hide • Fault finding and EMI • Trigger on transient events and intermittent signal • Complex R&D problems • Trigger on any change on your signal’s frequency domain view Intro to RTSA

  43. Real-Time Spectrum Analyzer • Trigger on small interfering signals • Capture a seamless record of Pre- and Post-interference activity • Analyze the effect of interference on the power, frequency and modulation over time Pre trigger time Post Trigger Time Trigger Point Intro to RTSA

  44. Real Time Spectrum Analysis Capabilities Continuous Trigger • Trigger is always “alarmed” – triggers, captures, displays and then waits for next trigger • Ideal for capturing a lot of information about a relativity slow or irregular repeating signal T1 T2 T3 T4 T5 Time Trigger Signal Memory Time Stamps T1 T2 T3 T4 T5 Intro to RTSA

  45. Three Measurement Modes Analyze • 1. S/A Mode: • Real-time spectrum analysis • Traditional spectrum analysis • 2. DEMOD Mode: • General purpose analog modulation analysis • General purpose digital modulation analysis • Standards based modulation analysis • 3. TIME Mode: • Time domain transient analysis • CCDF analysis Intro to RTSA

  46. S/A Mode - Real-time S/A Analyze • Real-time Spectrum Analysis • Max capture bandwidth is 10,15 or 36 MHz for RF signals and 40 or 20 MHz for baseband IQ signals (depending on the RTSA model). • # of FFT points is fixed at 1024 with Blackman-Harris 4B window • The acquisition length may include up to 64,000 frames • There is no post-FFT resolution bandwidth processing or averaging (RBW is determined by span setting) • All triggering modes available Intro to RTSA

  47. S/A Mode - Spectrum Analyzer Analyze • Traditional Spectrum Analysis • For wide spans, the measurements are similar to a swept spectrum analyzer since the full span is not measured simultaneously. A wide span is measured in 10 MHz steps. • Acquisitions are made on a frame-by-frame basis, not in long acquisition blocks of many frames • Includes wide span, RBW filtering, FFT setup, and averaging (not available in Real-Time S/A mode) • No trigger functions available Intro to RTSA

  48. Demod Mode Analyze • Analog modulation analysis • AM, FM, PM • General purpose digital modulation analysis (Opt 21) • 16QAM, 32QAM, 64QAM, 128QAM, 256QAM, BPSK, QPSK, π/4 DQPSK, 8PSK, GMSK, GFSK, PDC, PHS, NADC, TETRA, CDPD, Bluetooth, 2ASK, 2FSK • Standards based analysis(only available WCA200A & RSA3408) • W-CDMA UL & DL cdma2000, 1xEV-DO, GSM/EDGE, HSDPA, WLAN 802.11 A/B/G. Intro to RTSA

  49. Time Mode Analyze • Transient Analysis • Power vs. time • Frequency vs. time • IQ vs. time • CCDF • Complementary Cumulative Distribution Function • Power statistics of RF signals Intro to RTSA

  50. Real Time Spectrum Analysis Capabilities Summary • What is Real Time Spectrum Analysis • Seamlessly capture and store a span of RF frequencies at once • Trigger, Capture, Analyze time varying and transient RF signals in real time • In-depth analysis with time correlated multi-domain views • Advantages • Trigger on signals that other spectrum analyzers miss • Capture fast moving or transient signals • Analyze changes in the signal over time without making multiple measurements Intro to RTSA

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