Vector Signal Generator. Arb and Real-Time Signal Generation. Arb and Real-Time Signal Generation

Transcription

1 Vector Signal Generator

2 Purpose To describe the differences between Arbitrary waveform generation (Arb) and real-time waveform generation To understand the difference between component test and receiver test To experience the flexibility of Arb signals To demonstrate the similarities between Arb and real-time waveforms To familiarize you with the external waveform creation tool Signal Studio Slide 2

3 Digital (I/Q) Modulation Format Modes The signal generator supports two types of baseband signal generation: Arbitrary waveform playback (Arb) mode Commonly associated with component test Can also be used for receiver test Real-time mode Is typically associated with just receiver test Slide 3

4 A Signal Generator Requirement for Digital Modulation To use either the ARB or Real-time features to create digital modulation, a vector signal generator must have an internal baseband generator (BBG): Baseband Generator Options Signal Generator Model Opt MSa/s 8 MSa Opt MSa/s 64 MSa Opt MSa/s* 8 MSa Opt MSa/s 8 MSa Opt MSa/s 8 MSa Opt MSa E4438C x x E8267D x x N52A/82A x x x x Memory is important for playing Arb waveforms. Slide 4

5 Arb Waveforms The Arb provides unlimited signal creation flexibility for a short amount of time. Customers typically use signals that are less than one minute in length. Slide 5

6 Arb Waveforms Used for testing both system components (such as amplifiers) and receivers. The signal generator generates a waveform and saves it to a file, so the waveform has a finite length. The signal generator then plays this file once or multiple times. The file can be stored on the signal generator and recalled for use later. Slide 6

7 Arb Waveforms The Arb generates various I/Q waveform types: User defined create your own waveform or develop new modulation schemes Standardized modulation schemes (W-CDMA, cdma, TD-CDMA, etc.) Slide 7

8 Arb Waveforms Some of the Arb waveform creation tools for standardized modulation schemes do not incorporate all of the coding and framing typically associated with these types of signals. These signal are used for component testing. Arb waveform creation tools that do incorporate the coding and framing can be used for both component and receiver tests. Slide 8

9 Arb Waveforms For the Arb waveforms that do not incorporate the coding and framing, their signal is statistically equivalent to the fully coded and framed signal. Includes Coding and Framing No Coding and Framing Slide 9

10 Arb Waveform Creation Tools The signal generator supports waveforms from both internal and external signal creation tools. Embedded (Internal) Tools Optional signal generator features that allow the signal generator to both create and play waveforms. Typically 4xx series of options. The BBG option also includes these tools: Custom waveform creation tool (E4438C & E8267D) Dual ARB Player only plays waveforms (E4438C, E8267D, N52A/82A) 400 W-CDMA 401 cdma2k Slide 10

11 Arb Waveform Creation Tools External Tools This refers to software tools used to create the waveform and then it is downloaded to the signal generator for playback. The signal generator still requires a BBG to store and play the waveforms. Typically N76xxA/B Model Number (requires license purchase) N7600B W-CDMA HSPA N7613A WiMAX EEsof ADS Connected Solutions Other Software Tools C++ MATLAB Visual Basic Agilent VEE Slide 11

12 Arb Block Diagram Internal arbitrary waveform generator block diagram (option 602) Signal Studio or Customer File Waveform memory BBG Memory in the MXG DSP IRAM 64 MSa Over - sampling DAC Filter I Data Generator Filter To I/Q modulator QRAM 64 MSa Over - sampling DAC Q Signal Studio or Customer File Waveform memory BBG Memory in the MXG Slide 12

13 Real-Time Signals Real-time signal creation tools do just what the name implies, they create the signal in real-time. There is no stored file, nor is the signal finite in length. Real-time tools provide limited signal creation flexibility for a long period of time. The modulation types are fixed. Customers may use signals that are minutes to hours long. Slide 13

14 Real-Time Signal Channel Coding Signals created for standardized modulation schemes (TDMA, cdma, W-CDMA, etc.) are fully coded and framed. Since the signals are fully coded, they can be used to test the entire receiver side of a system. Great for BER testing. Slide 14

15 Real-Time Block Diagram Customer User File (6.4MB) Created in DSP and continuously streamed to DAC Over - sampling DAC Filter I Repeated indefinitely Data Generator Built-in data patterns I/Q Symbol Builder Over - sampling DAC Filter Q External Data input Infinite data length Use for BER and BLER testing Slide 15

16 Real-Time Signal Creation Tools Real-time (RT) signal creation tools also include both embedded and external products. Embedded Tools Just like the Arb, there are optional signal generator features that allow the signal generator to create real-time signals. Typically 4xx series of options. 400 W-CDMA (A 4xx option can contain both RT & Arb tools) 401 cdma2k The BBG option also includes this tool: Custom signal creation tool (E4438C & E8267D) The N52A/82A MXG supports only two real-time capabilities: Option 403 AWGN and Option 432 Phase Noise. Slide

17 Real-Time Signal Creation Tools External Tools The signal generator still requires a BBG to create the signals. Typically N76xxA/B Model Number (requires license purchase) (A signal studio product is either real-time or Arb based.) Other Software Tools C++ MATLAB Visual Basic Agilent VEE Embed SCPI commands in the code to create the signal. Slide 17

18 Summary Arb Used for both component and receiver testing. Provides unlimited signal creation flexibility for a short amount of time. Real-Time Primarily used in receiver testing. Provides limited signal creation flexibility for a long amount of time. For information about signal creation tools (embedded and external) visit: Slide 18