Continuous Waveform (CW) Carrier

The N7625C Signal Studio Pro for LTE/LTE-Advanced TDD 2024 Update 1.1 software enables you to generate a Continuous Waveform (CW) carrier.

A typical receiver measurement is the receiver's ability to continually demodulate in the presence of an interferer signal. These signals are often simulated with a CW blocker. Using the N7625C you can generate one or more CW signals for these types of measurements.

Typically, the wanted signal is at a lower power level than the unwanted signal (interferer). As the dynamic range increases between the wanted and unwanted signals, the EVM for the wanted signal is degraded.

In some cases, better RF performance is required or you may need a dynamic range that is greater than the software's -60 dBm dynamic range. For these cases, additional signal generators can be used to generate the CW interferer waveforms and to then combine the waveforms in RF to minimize the intermodulation products and to improve EVM performance.

In the figure below, a Continuous Waveform is selected for configuration.

1. General
State
2. Baseband
Oversampling Ratio
Baseband Sampling Rate
Total Sample Points
Frequency Offset
Power

1. General

State

Double-click or use the drop-down menu to control the operating State of the UL-SCH carrier

2. Baseband

Oversampling Ratio

This is a read only parameter. This parameter is not editable.

Baseband Sampling Rate

Displays the Baseband Sample Rate. This parameter is not editable.

Total Sample Points

View the Waveform Length, displayed in points.This parameter is not editable.

Waveform Length is directly related to the Oversampling Ratio value selected. The higher the Oversampling Ratio, the larger the waveform.

Frequency Offset

Range: -76.8 MHz to 76.8 MHz

Default: 0 Hz

Sets the frequency offset for the carrier relative to the signal generator’s frequency setting.

This parameter is coupled with Oversampling Ratio.

Maximum Frequency Offset for each Maximum Arb Sample Clock
Maximum Arb Sample Clock (RF Bandwidth)	Maximum Frequency Offset
75 MHz (60 MHz)	15.36 MHz
100 MHz (80 MHz)	30.72 MHz
125 MHz (100 MHz)	46.08 MHz
150 MHz (120 MHz)	46.08 MHz
200 MHz (160 MHz)	76.8 MHz

Power

Range: -60.000 to 20.000 dB

Default: 0.000 dB

Sets the carrier’s power relative to the signal generator’s amplitude setting.