Custom Arb Waveform Generator

Working with Modulation Types

To Use a User-Defined Modulation Type (Real Time I/Q Only)

Creating a 128QAM I/Q Modulation Type User File with the I/Q Values Editor

In I/Q modulation schemes, symbols appear in default positions in the I/Q plane. Using the I/Q Values editor, you can define your own symbol map by changing the position of one or more symbols. Use the following procedure to create and store a 128- symbol QAM modulation.

NOTE Although this procedure provides a quick way to implement a 128QAM modulation format, it does not take full advantage of the I/Q modulator’s dynamic range. This is because you begin with a 256QAM constellation, and delete unwanted points. The remaining points that make up the 128QAM constellation are closer together than if you had mapped each point specifically. Additionally, this approach does not enable you to define the bit pattern associated with each symbol point, as you could if the 128QAM constellation had been defined one point at a time.

1.Press Preset.

2.Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User I/Q > More (1 of 2) > Load Default I/Q Map > QAM > 256QAM.

This loads a default 256QAM I/Q modulation into the I/Q Values editor.

3.Press More (2 of 2) > Display I/Q Map.

In the next steps, you will delete specific portions of this I/Q constellation and change it into a 128QAM with 128 I/Q states.

4. Press Return > Goto Row > 0011 0000 > Enter; this is row 48.

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Agilent Technologies E8267D PSG, E8257D PSG manual To Use a User-Defined Modulation Type Real Time I/Q Only
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E8267D PSG, E8257D PSG specifications

Agilent Technologies, a recognized leader in electronic measurement and communications solutions, offers a comprehensive range of signal generators, including the E8257D PSG (Pulsed Signal Generator) and E8267D PSG. These instruments are engineered to meet the demanding requirements of wireless communication, aerospace, defense, and various research applications.

The E8257D PSG is known for its versatility and reliability. It operates within a frequency range of 250 kHz to 40 GHz, making it suitable for a wide array of applications, from signal generation to vector modulation. With an output power capability of up to +30 dBm, it delivers high-quality signals with exceptional precision. Its low phase noise performance is especially critical for applications such as radar and communication system testing, where signal integrity is paramount.

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On the other hand, the Agilent E8267D PSG is designed to cater to the needs of users requiring a combined signal generation and analysis solution. With the capability to generate signals from 250 kHz to 67 GHz, the E8267D is ideal for millimeter-wave applications, as well as testing next-generation wireless technologies.

This model includes features such as enhanced phase noise performance and faster switching speed, which are crucial for signal integrity in sophisticated networks. The instrument's intuitive user interface and powerful software integration facilitate effortless operation and automation, thereby improving workflow efficiency.

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