MIMO OTA TEST LEADER
October, 2011
8x8 MIMO Analyzer:The MIMO OTA Test Leader
PDFファイルWith the first 4G networks deployed in 2011 and the compulsory use of MIMO into both WiMAX and LTE
standards, MIMO technology has finally exploded.
Mobile Internet Peripherals and Devices are said to take a market share of 30% of all handsets and non‐handsets wireless devices by 2013, but need to be extensively tested before commercialization. The unique features of the MIMO Analyzer which make MIMO measurements simple are described in this document, which really exhibit a world class leader for MIMO OTA research, development, pre‐compliance, compliance and performance testing.
- I. Introduction
- In an unprecedented performance, the MIMO Analyzer provides for the most extensive number of test parameters and figures of merit for MIMO passive and active OTA research, development, pre-compliance, compliance and performance testing.
- II. Measured Parameters
- The parameters that can be tested using the MIMO Analyzer are:
- A. MIMO Passive performance parameters
1. Correlation Pearson (H)
2. Correlation Blanch (S)
3. Mutual Coupling (MC)
4. Radiation Efficiency (η)
5. Total Radiation Efficiency (ηT)
6. Diversity Gain (ADG, AcDG, EDG, IDG)
7. Diversity Gain Loss (DGL)
8. Mean Effective Gain (MEG)
9. Effective MEG (EMEG)
10.Branch Power Ratio (BPR)
11.MIMO Capacity (CMIMO)
12.MIMO Capacity Loss (CLMIMO)
13.Number of Scatters (NS)1
14.Power Angular Spectrum (PAS)1
15.Angle of Arrival (AoA)1
16.Angular Spread (AS)1
17.Channel-fading K-factor (K)
18.Eigenvalues (i)
19.Number of Multipath Components (MPC)1
20.Cumulative Density Function (CDF)
21.Power Density Function (PDF)
22.Scatterplot (S)
23.Non-isotropic measurements (NISO)
24.Arbitrary Fading Emulation Sample Selection (SS)2
The EMITE mode-stirred reverberation chambers have the capability to emulate any K-factor (satisfactorily validated up to K=100) for Rician fading, the use of 5 different isotropic scenarios with/without phantoms (VZW defined as FS, BH, BHHR, HR and 3GPP defined as LME-support for notebooks), and, at date of print, a limited set of 7 different non-isotropic scenarios including single- and multiplecluster ones. This represents an emulating capability of 1 (Rayleigh) x 1 (isotropic) x 5 (FS/phantom/LME) x 100 (Rician) x 7 (non-isotropic) scenarios, a total of 3500 different scenarios. With these 3500 scenarios the user can cover 95% of the scenarios wherein the terminal is supposed to operate, with a few exceptions like keyholes or Hyper-Rayleigh. Within 2012 we intend to release the user’s capability to measure its emulated PAS and to use arbitrary amplitude PDFs through sample selection (already demonstrated for on-body and IEEE 802.11n fading models), and therefore open the emulating capability to infinite scenarios. All these measurements are provided versus SNR for the measured frequency bandwidth or versus frequency for a specific SNR.
In contrast to the only capability of isotropic Rayeigh-fading testing of our competitors, the MIMO Analyzer can provide true realistic testing in the laboratory, including diverse correlation and mutual coupling parameters. All tested scenarios have been validated with real measurements and presented at IEEE, COST,CTIA and 3GPP meetings and journals. No other company offers the channel-related parameters measurements like the Power Density Function, K-factor or the Eigenvalues. All these parameters allow the user to clearly identify the tested scenario and characterize the DUT in an unprecedented way. Most available Anritsu2, Rohde & Schwarz and Agilent Technologies Vector Network Analyzers (VNA) can be used with the MIMO Analyzer.
The MIMO Analyzer is controlled using a Front Control Panel, and calibration up to these front panel connectors is the only requirement. The GUI employs efficient and fast de-embedding algorithm for enhanced repeatability. Recalibration of internal cable and switch losses is recommended every two years and can be done locally without any de-assembling. Yet, the MIMO Analyzer comes with easily demountable panels for access to maintenance parts. All electronic devices, cables, switches, etc. are not placed inside the measurement cavity, therefore ensuring a noise- and interference-free 100 dB isolation.- B. MIMO OTA Active power parameters
The EMITE Graphic User Interface (GUI) software allows complete overnight automatic measurements of any set of standardized active MIMO OTA measurements with the settings loading option. TRP measurements can be as fast as 1 minute, and the Fast TIS Estimation can provide accurate values within 3 minutes.
1. Total Radiated Power (TRP)
2. Total Isotropic Sensitivity (TIS) /
Total Radiated Sensitivity (TRS)
3. MIMO TIS
4. MIMO TRP
5. MIMO Throughput Effectiveness (MTE)3
6. CQI
7. BER3
8. Air Interface MIMO Throughput (AI-TPUT)
9. Active Antenna Gain (AAG)3
10.MIMO Receiver Sensitivity3
11.MIMO Device Efficiency3
Stirring can be done through mechanical stirring (paddle(mode)- and platform-stirring) and electronic stirring (frequency-, time- and source-stirring). The aim of stirring is simply to enrich the number of independent measurements, as in a mode-stirred reverberation chamber the only thing that ensures accurate final results is a large number of independent measurements. An excellent isotropic accuracy of ±0.05 dB is provided with source-stirring only in the MIMO Analyzer for 2x2 and 4x4 systems thanks to the unique dual-cavity slotted-coupled technique. Additional platform-stirring is provided for 8x8 systems to ensure the same isotropic accuracy. A repeatability of ±0.1 dB is also provided. MIMO TRP and MIMO TIS employ the recently-released Verizon Wireless multiport evaluation of TRP/TIS with manual and automated primary and secondary MIMO receiver enabling and disabling processes, providing up to 16 different TIS values per channel in LTE DUTs.- C. MIMO Manual parameters
In addition to conventional active and passive parameters, the MIMO Analyzer also offers a unique Manual measurement mode wherein real base stations can be connected to the mode-stirred reverberation chamber to perform diverse measurements. These measurements include:
1. Power Delay Profile (PDP)
2. Variable PDP3
3. Root Mean Square Delay Spread (RMS DS)
4. Variable RMS Delay Spread3
5. MIMO VRC Measurements - Manual
6. Downlink TCP MIMO Throughput (DL TCP TPUT)
7. Uplink TCP MIMO Throughput (UL TCP TPUT)
Some of these parameters are uniquely offered by EMITE. Of particular interest is the Variable Reference Channel (VRC) measurements, which has already been used successfully for measuring a real LTE eNodeB and a UE connected to the modestirred reverberation chamber for the first time. With the ergonomic design of the MIMO Analyzer, the user is allowed to set stirrer’s velocity and time of emulation. Similarly, any technology that is able to establish a TCP/IP connection can be connected to the MIMO Analyzer for evaluation of both downlink and uplink TCP Throughput.
All these measurements can be performed with both low noise and high noise settings through EMITE’s GUI Client software. In low noise, the power of host PC is on during measurements but no other function is used. Two different high noise settings can be activated (independently or simultaneously). The power of the host PC is being on during measurements and in addition to this a SD memory card is being read continuously or/and an “H” character is being written continuously in a command prompt window.
Most available Anritsu, AT4 wireless, Rohde & Schwarz and Agilent Technologies Base Station Emulators (BSE) can be used with the MIMO Analyzer. Likewise, the MIMO Analyzer can used in connection to a Channel Emulator (CE) for MIMO 3GPP SCME injection.
- III. Operation
-
The E400 MIMO Analyzer measures 2855(L) x 1515(W) x 2000(H) mm3. Up to 8-element passive antenna RF front ends can be tested in passive mode using the MIMO Analyzer. EUTs as large as 40 cm in the largest dimension can be measured.
The following technologies can be tested with the MIMO Analyzer MIMO OTA active mode:Cellular standards:
GSM Family: GSM 4004/850/900/1800/1900, GPRS, EGPRS
WCDMA Family: FDD WCDMA (UMTS), HSDPA/HSUPA, HSPA+
LTE Family: LTE FDD, LTE TDD4
CDMA Family: CDMA2000 (1x), CDMA2000 (1xEVDO) Rev 0, CDMA2000 (1xEVDO) Rev AWireless standards:
IEEE 802.11a/b/g (WiFi)
IEEE 802.11n (WiFi MIMO)
IEEE 802.16 (WiMAX)
IEEE 802.15.1 (Bluetooth)4
By default the MIMO Analyzer can measure up to 8x8 MIMO passive parameters and up to 2x2 active MIMO OTA figures of merit, allowing testing of any Dual Cell (DC) technology also. The 4x4 and 8x8 upgrades allow testing of Quadruple Cell (QC) technologies. The MIMO Analyzer provides measured samples with mechanical(mode)-stirring, source-stirring and frequency-stirring. Additionally, 8x8 upgrades include platformstirring.
- IV. Accuracy
-
Six different accuracy testing modes can be selected in the MIMO Analyzer
Extremely Fast measurements (only Fast TIS Estimation)
Very Fast measurements
Fast measurements
Accurate measurements
Very Accurate measurements
Customized measurements
The Extremely Fast measurements provide a quasi-immediate prediction of TIS using a continuous stirrer movement. Fast TIS Estimation (FTE) measurements can take between below 1 minute (GSM) to 3 minutes (LTE).
Very Fast measurements are setup to use simultaneous mechanical stirring mode, 2x2 stirrers positions, source stirring, and coherence-bandwidth frequency stirring. In a 2x2 LTE MIMO system in Band 7, with 1601 frequency points and 25 MHz frequency stirring bandwidth this accuracy mode would provide 653.208 measured samples per receiving antenna in less than 1 minute. Accuracy in Very Fast mode complies with CTIA standard (STD ±2 dB TRP, STD ±2.25 dB TIS).
Fast measurements are setup to use simultaneous mechanical stirring mode, source stirring, 5x5 stirrers positions and coherence-bandwidth frequency stirring. In a 2x2 LTE MIMO system in Band 7, with 1601 frequency points and 25 MHz frequency stirring bandwidth this accuracy mode would provide 1.633.020 measured samples per receiving antenna in less than 3 minutes. Accuracy in Fast mode ensures STD ±1 dB TRP, STD ±1.25 dB TIS.
Accurate measurements are setup to use simultaneous mechanical stirring mode, source stirring, 15x15 stirrers positions and coherence-bandwidth frequency stirring. In a 2x2 LTE MIMO system in Band 7, with 1601 frequency points and 25 MHz frequency stirring bandwidth this accuracy mode would provide 4.899.060 measured samples per receiving antenna in less than 25 minutes. Accuracy in Accurate mode ensures STD ±0.3 dB TRP, STD ±0.5 dB TIS.
Very Accurate measurements are setup to use semi-simultaneous mechanical stirring mode, source stirring, 15x15 stirrers positions with step 5 and coherence-bandwidth frequency stirring. In a 2x2 LTE MIMO system in Band 7, with 1601 frequency points and 25 MHz frequency stirring bandwidth this accuracy mode would provide 19.596.240 measured samples per receiving antenna in less than 90 minutes. Accuracy in Very Accurate mode complies with CTIA standard (STD ±0.2 dB TRP, STD ±0.2 dB TIS).
The Customized mode allows the user to set all the different possibilities, including frequency stirring bandwidth, frequency points, stirrers’ positions and mechanical stirring mode, leading to both extremely fast modes and extremely accurate modes. The total number of samples (TNS) taken with the diverse accuracy modes follows the formula,
where Tx is the number of employed transmitting antennas (8 with source-stirring activated), Rx is the number of receiving antennas, Stirpos is the total number of stirring positions combinations, fp is the number of frequency points, f is the frequency stirring bandwidth and B is the measured bandwidth.
These measurement options can be selected prior to both calibration of the MIMO Analyzer and the running of the measurement.
- V. Options and accessories
-
Optional accessories include:
‐ 5 or 10 A DC filter and penetration
‐ 5 or 10 A AC filter and penetration
‐ Circular wave guide (6 mm to 12 mm diameter) penetration
‐ Fiber optic (8- or 12-way) pipe penetration
‐ Ethernet filter and penetration (10/100baseT(X) to 100baseFX fiber connector)
‐ USB 2.0 filter and penetration (5V 2A)
‐ USB 2.0 filter and penetration (USB fiber converter)
‐ RJ45 fiber optic convertor (1 pair)
‐ RS232 fiber optic convertor (1 pair)
‐ Rotating platform
‐ SAM/SHO phantom packages
‐ Diskcone reference antennas
‐ Dipole reference antennas
‐ Absorbing pieces
‐ Metallic pieces for non-isotropic measurementsOptional components include:
‐ Pneumatic door
‐ Internal mushroom-type emergency stop button
‐ Double-sided handle indoor
‐ Retractable foot-brake
‐ Active 4x4 matrix-switching Module
‐ Active 8x8 matrix-switching Module
The EMITE rotating platform allows additional platformstirring for active 8x8 MIMO OTA measurements using the E400 with a slewing ring polymer bearing. The sliding pads in both the platform and stirrers are German-made from high-performance polymers and are completely free from maintenance and lubrication. All the housing components are made from anodized aluminum and the surfaces which mate with the sliding pads are all hard anodized.
The MIMO Analyzer comes with a pedestal (40 cm x 30 cm) for easy DUT positioning, which serves several hosting platforms (SAM phantom, host PC platform, handset positioner and reference antenna positioner) with 6 interchangeable pieces.
- VI. Control Software
-
The MIMO Analyzer Graphic User Interface (GUI) software is an intuitive and easy-to-use interface with the user.The software performs all settings of auxiliary equipment (VNA, BSE) as well as the MIMO Analyzer itself, detects licensed performance, runs measurements and plots/saves/export measured results. With the MIMO GUI there is no need to use any other software for complete MIMO measurements. The selected measurements settings and its impact on measurement accuracy and measurement time is prompted to the user prior to measurements.
A measurement progress information bar is also available for the user, who can pause or cancel measurements on the run, savings intermediate results if available. Results and calibration files are saved in text-format and binary files that can be later re-used or imported. Plotting facilities include zoom (in/out), pan, rotate, 3D, data cursor and insert (color bar/legend), among others. Exporting data to over 15 different graphic, text and binary formats including Matlab™-compatible ones is also possible with the MIMO Analyzer GUI.
お問い合わせ
株式会社ネットウエル 無線通信営業部
電話：03-5368-3453
オンラインでのお問い合わせはお問い合わせフォームから
