1. 5G Waveform Generation and Analysis Require Flexibility

A major challenge of current 5G researchers is that the waveform, frequency and bandwidth of 5G research are too numerous or varied. This includes waveform below 6 GHz, as well as microwave and millimeter wave waveform that may involve high bandwidth. In response to so many possible scenarios, a flexible test environment is critical to this phase of 5G signal generation and analysis. Navigation, aviation, aerospace, radio and television, broadband wireless networks, Internet of Things and many other fields.

2. 5G Waveform Generation and Analysis Test Challenge

Flexibility is essential for 5G research. It supports the implementation of “what if” analysis using modulation schemes in multiple different frequency bands and modulation bandwidths during the evaluation of early concepts and 5G candidate waveform. There are significant risks associated with choosing the wrong path, further enhancing the need for flexibility, especially in signal creation and signal analysis tools. As many candidate waveforms continue to emerge during the evolution of 5G, these tools must be able to make adjustments and changes quickly.

When developers perform the experiments, a highly flexible test bench will help them evaluate the proposed waveforms through prototype algorithms and hardware. It also enables quick and easy conversion between simulated hypothetical scenarios and real-world testing of prototype algorithms and hardware.

More specifically, 5G research and early testing require flexibility in three main areas:

— High fidelity generation and analysis of Pre-5G and multiple system waveform

— Support for larger modulation bandwidths from 100MHz to 5GHz

— Supports larger frequency bands from RF to Cm wave to millimeter wave

3. 5G Waveform Generation and Analysis (28-39GHz)

To help solve these test challenges, the 5G waveform generation and analysis reference solution combines the hardware, software, and professional measurement techniques to provide the essential components for building a flexible 5G waveform generation and analysis test platform. The reference solution enables engineers and researchers to generate and analyze 5G candidate waveforms for RF, CW and millimeter wave frequencies with modulation bandwidths up to 2 GHz, with a focus on Pre-5G development at 28 GHz and 37-39 GHz. Combine 5G candidate and custom waveform signal creation software with two hardware (a precision AWG and a vector signal generator with wide I/Q inputs) for up to 44 GHz (using upconverter capability) Broadband test signals with modulation bandwidths up to 2 GHz are generated at higher frequencies. For signal demodulation and analysis, the software can be used internally in simulation software or on signal analyzers, oscilloscopes or PCs to control a variety of instruments or digitizers. The physical picture of the S1465V series vector signal generator produced by Saluki Technology is shown in Figure 1.

Fig.1 Saluki S1465V Series Vector Signal Generator

4. Signal Generation Configuration

For Pre-5G and 5G new wireless signals in the 28 and 39 GHz bands, the new S1465V microwave signal source delivers 1% EVM directly in bandwidths up to 1 GHz without the need for external probes or components. For bandwidths above 1 GHz, an external arbitrary waveform generator is required. The S1465V wideband external IQ input option can be increased up to 2GHz bandwidth. To generate signals above 44 GHz, an upconverter (50-110 GHz) is required. The microwave analog signal generator provides a local oscillator for the millimeter wave upconverter. Saluki Technology is working on software for generating signals. First, the software for Pre-5G and for custom modulation is a very flexible tool that can generate signals directly. They feature a parametric graphical user interface (GUI) that makes it easy to create Pre-5G waveforms or customize FBMC, I/Q, and OFDM waveforms. Customized OFDM and I/QVSA setup files can be saved for EVM testing using a variety of signal analyzers and oscilloscopes. In addition, the Signal Optimizer software integrates some of the signal generation and analysis functions and adds calibration to the input and output sides of the device under test. When used in conjunction with a comb signal calibrator, the EVM performance degradation caused by the use of external cables and fixtures can be eliminated, resulting in the highest possible quality of EVM events on the true input side of the device under test. This is especially critical for low-reflection and nonlinear devices because these devices are particularly sensitive to undesired system states such as in-phase and quadrature flatness versus frequency and frequency dependent losses. This signal optimizer software works well with other software.

5. Signal Analysis Configuration

For backhaul and higher millimeter-wave bands with bandwidths up to 5 GHz, an oscilloscope’s precision downconverter is required, which samples the IF. To achieve higher bandwidth, you can also use an ultra-wideband oscilloscope to sample the signal at millimeter-wave frequencies (no need to use a downconverter). These test signals can be used with the signal analyzer software for analysis. In addition, custom I/Q-specific software can be used.