MIMO RF Signal Analysis and Generation Test System

The 2800-MIMO RF Signal Analyzer and 2900-MIMO RF Signal Generator are high-performance MIMO test systems designed to meet the needs of 802.11n WiFi and 802.16e Mobile Wi-MAX Wave 2 multiple-input multiple-output communication standards. The 2820 RF Signal Analyzer and 2920 RF Vector Signal Generator can be used to configure a two-, three-, or four-channel system with a 40MHz signal bandwidth. These instruments have built-in hardware connections and related firmware to support MIMO functions.

These MIMO systems can be initially configured as 2×2 systems and then upgraded to three or four channel systems by adding a standard 2820 or 2920. Furthermore, these instruments are not necessarily dedicated to MIMO systems. By selecting configurations in the firmware and changing some backplane cables, these instruments can be configured as MIMO systems or used as standalone SISO (single input single output) instruments.

The 2820 RF Vector Signal Analyzer and 2920 RF Vector Signal Generator are mid-range test instruments for R&D and production testing of modern RF communications equipment and devices. They are built on a new generation instrument platform that uses the latest RF and DSP (digital signal processor) technology. This enables them to quickly measure and generate RF signals without sacrificing accuracy and repeatability.

Both the 2820 and 2920 support MIMO functionality and have the hardware and software architecture required to configure a MIMO test system. With simple reconfiguration, they can also be configured as standalone test instruments or configured into a MIMO test system. This flexibility is very useful for users who do not want to make a large investment in a MIMO system but need this function when necessary. The 2820 RF Vector Signal Analyzer configured with the optional 2820-80211 WLAN 802.11 Signal Analysis Special Tool can measure all 802.11a, b, g, j and n SISO signals. This special tool can automatically detect the modulation type. It has multiple measurement display windows, including constellation diagrams, EVM per channel, EVM per symbol, CCDF, etc. Depending on the type of signal, a full set of signal measurements can be completed in 17 to 50ms.

The 2920 provides an optional arbitrary waveform generator (ARB) with a waveform storage depth of 100M samples and a bandwidth of up to 80MHz, which can generate WLAN, WiMAX and any other test signals required by users. The 2920's ARB memory can store multiple different signal waveforms at the same time. Using SCPI commands, you can switch between any two waveforms within 3ms, and using ARB Sequence mode, you can switch even faster. When using List mode or ARB Sequence mode, the frequency switching time is 1.3ms, and when using SCPI commands, the switching time is 3ms. This greatly speeds up the test time of RF devices that require multiple test frequencies, multiple test signals, or both.

Beamforming is one of the main performance advantages of Keithley's 2800 series vector signal analyzers and 2900 series vector signal generators. They can aim the energy of RF communication to the designated user by adjusting the phase and amplitude of each related transmitter or receiver in beamforming. At present, the research on beamforming mainly focuses on the development of higher-configuration wireless communication equipment to provide users with the maximum number of services as possible. 8×8 and higher-configuration wireless communication technology is the mainstream of broadband wireless communication research. Keithley provides the industry's only 8×8 level phase correlation measurement system. [page]

MIMO Synchronization Unit Model 2895 provides synchronized signals to system instruments. This feature enables highly accurate and stable alignment between up to four signal analyzers or signal generators. MIMO Synchronization Unit Model 2895 provides a common LO (local crystal), common clock, and precise triggers for all signal analyzers or generators connected within the system. This highly accurate alignment enables the system to make precise and repeatable OFDM (Orthogonal Frequency Division Multiplexing) MIMO signal measurements.

The RF carrier phases of all instruments in each system are synchronized with each other, without restriction to the use of phase-locked loops. The peak-to-peak phase jitter of the RF carrier phase between any two instruments is less than one degree. In addition, the signal samplers of these MIMO system instruments are precisely aligned. The maximum sampling time difference of the system is 1ns, and the peak-to-peak sampler jitter between any two instruments is less than 1ns.

MIMO Signal Analysis Software

280111 WLAN 802.11n MIMO Signal Analysis Software is an industry-leading suite of PC tools. This fast and powerful software includes a rich measurement suite for analyzing 802.11n WLAN device signals with up to 16 4×4 MIMO channels.

The software's GUI configuration process is fast and easy, and the interface to the test system is achieved through the SCPI command set. It can stream data from up to four 2820s to a PC, analyze all received signals, and display the results. It can automatically detect the MCS (modulation coding scheme) of 802.11n. Its extensive measurement capabilities include SISO measurements such as error vector magnitude (EVM), as well as frequency error and MIMO measurements such as channel response and mutual power (i.e. transmitter isolation).

The new generation of RF test instruments launched by Keithley can meet the challenges faced by designers and manufacturers in the current wireless technology and business fields. Their bandwidth can test current wireless devices and is also suitable for the needs of most future new technologies. They have the flexibility to test multiple signals and can be used in the test structure of SISO and MIMO tests. In addition, they have extremely high measurement accuracy, which can ensure high product quality and production yield, and also have high test speed and low equipment cost required to reduce test costs, thus meeting the needs of business.