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WSA5000 Functional Overview

If the application only needs to utilize up to 50MHz of IBW, a simple alternative to DC
offset compensation is to use the SH mode of operation.

IQ Offset Correction

Direct-conversion receivers have phase and/or amplitude offsets between in-phase (I)
and quadrature (Q) components of the baseband signal. Due to this, when an FFT is
performed on digitized baseband data where there is a signal tone present, there will be
an ‘image’ at the same frequency offset from the center frequency as the tone itself. This
is illustrated in

To compensate for this, the raw I and Q data must be processed according to the
following “calibrateIQ” routine, illustrated using the following MATLAB® code. When an
FFT is performed on the output of calibrateIQ, the image will disappear. This process has
no impact on the accuracy or precision of the data.

%%%%%
% MATLAB code for IQ Offset Correction
%%%%%

function [calibratedQ] = calibrateIQ(iData, qData)

numberOfSamples = size(iData, 1);
sumOfSquaresI = sum(iData.^2);
sumOfSquaresQ = sum(qData.^2);
amplitude = sqrt(sumOfSquaresI * 2 / numberOfSamples);
ratio = sqrt(sumOfSquaresI / sumOfSquaresQ);
p = (qData/amplitude) * ratio .* (iData/amplitude);
sinphi = 2 * sum(p) / numberOfSamples;
phi_est = -asin(sinphi);

calibratedQ

=

((sin(phi_est)

*

iData)

+

(ratio

*

qData))

/

cos(phi_est);

end

Signal

Image

XdB

Frequency

F

c

Frequency

F

c

Fc+Fs

Fc-Fs

calibrateIQ

19

ThinkRF WSA5000 Wireless Signal Analyzer Programmer's Guide

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Содержание WSA5000 Series

Страница 1: ...r s Guide December 01 2016 Document no 75 0014 150216 Copyright 2013 2014 2015 2016 ThinkRF Corporation All rights reserved All product names are trademarks of their respective companies This document...

Страница 2: ...ranty policy all costs of repairs and shipping will be charged directly to the Customer ThinkRF will warrant repaired units for a period of 90 days from date of shipment from ThinkRF to the Customer I...

Страница 3: ...gital Down Converter 21 Triggers 21 Frequency Domain Triggering 22 Periodic Triggering 23 External Triggering 23 Capture Controller 23 Trace Capture Control 24 Sweep Capture Control 24 Synchronized Sw...

Страница 4: ...CONFigure 47 SYSTem COMMunicate LAN DNS 48 SYSTem COMMunicate LAN GATEway 48 SYSTem COMMunicate LAN IP 48 SYSTem COMMunicate LAN NETMask 49 SYSTem ERRor NEXT 49 SYSTem ERRor ALL 50 SYSTem FLUSh 50 SY...

Страница 5: ...Version 69 TRIGger Commands 69 TRIGger TYPE 69 TRIGger LEVel 70 TRIGger PERiodic 70 TRIGger STATus 70 TRACe Commands 71 TRACe BLOCk DATA 71 TRACe BLOCk PACKets 72 TRACe SPPacket 73 TRACe STReam STARt...

Страница 6: ...ommand Syntax 85 Entering Commands 85 Notation 86 Parameter types 86 Default Units 87 Appendix SCPI Status and Event Registers 88 Status Byte Register SBR 88 Standard Event Status Register ESR 88 Oper...

Страница 7: ...onics Engineers IF Intermediate Frequency IQ In phase and Quadrature IQIN External I and Q Input LAN Local Area Network MB Mega Bytes MSB Most Significant Byte NB Narrowband NCO Numerically Controlled...

Страница 8: ...6 Association between Time and Frequency Domain 22 Figure 7 Synchronized Sweep using Sync Word 27 Figure 8 Synchronized Sweep with a Missed Capture 27 Figure 9 Connectivity and 4 Different Packet Stre...

Страница 9: ...evel Field Format 34 Table 20 RF Frequency Offset Word Format 34 Table 21 Extension Context Packet Class Structure 35 Table 22 Extension Context Indicator Field Positions 35 Table 23 Receiver Context...

Страница 10: ...ink to the referenced source that can be clicked on Normal Bold Font When used within a sentence or a paragraph it emphasizes an idea to be paid attention to particularly Red Font Conveys special info...

Страница 11: ...customers who hold a valid end user license ThinkRF provides technical assistance 9 AM to 5 PM Eastern Time Monday to Friday Contact us at support thinkrf com or by calling 1 613 369 5104 Before conta...

Страница 12: ...and or distributed wireless signal analysis It is ideal for monitoring management and surveillance of transmitters whether they are in building or spread across a geographic area Applications include...

Страница 13: ...applications The Python API is built within the PyRF development framework and is open source under BSD licensing PyRF handles the low level details of real time acquisition signal processing and visu...

Страница 14: ...tion that has the lock can perform the task OPTions Returns comma separated 3 digit values to represent the hardware option s or features available with a particular WSA model SYNC MASTer Sets a WSA u...

Страница 15: ...are connecting to the unit it is advised that only one of those is controlling the unit at any time The Architecture The WSA5000 is an integrated wireless radio receiver and digitizer analyzer It has...

Страница 16: ...and Capture Controller Functional Block Diagram The WSA5000 supports different RFE modes of operation and subsequent DSP capabilities as per Table 2 and as described in the following subsections Thin...

Страница 17: ...Hz for non WBIQ models and 55MHz for WBIQ models will be applied automatically to bring the WSA5000 s center frequency back to the zero IF Thus the data output will be I and Q 5 IQIN mode is not avail...

Страница 18: ...m the external RF IN or I and Q IN ports respectively Hence neither of these modes support frequency tuning of the radio although the DSP s frequency shift mode may be applied Direct Conversion Receiv...

Страница 19: ...Q data must be processed according to the following calibrateIQ routine illustrated using the following MATLAB code When an FFT is performed on the output of calibrateIQ the image will disappear This...

Страница 20: ...of the RFE IF Queries the IF frequencies that are used for the current input mode and center frequency LOSCillator Gets the frequency to be set for the external LO 1 or 2 in corresponding to current...

Страница 21: ...CIC filters with a FIR filter combined The CIC filter has a droop associated with it in the passband In order to compensate for this droop the CIC filter is followed by a compensating FIR filter Each...

Страница 22: ...sociation of the time domain and the frequency domain The internal frequency domain data lags the time domain data by 1024 samples at the rate of 125 MSa s After a trigger event is detected the subseq...

Страница 23: ...Contact ThinkRF s Support for details on how to use the GPIO port prior to connecting anything to the port Table 4 Trigger Control Status Commands SCPI Command Description TRIGger Page 69 TYPE Sets o...

Страница 24: ...riggering and continuously on best effort basis in other words data might not be continuous from one packet to the next once the internal buffer is full The execution of the trace capture could be con...

Страница 25: ...s the list is repeated during execution STARt Begins execution of the current sweep list from the first entry STATus Get the current sweep status STOP Stops execution of the current sweep list ENTRy A...

Страница 26: ...YNC MASTer ON and the other WSA5000s are configured as slaves SYSTem SYNC MASTer OFF The master and slaves are configured with a sweep list in which each sweep entry has a synchronization trigger type...

Страница 27: ...slave s delay then the slave will miss the beginning of the capture The host side application that is collating the capture data may recognize the missed capture by noting the timestamps and or freque...

Страница 28: ...re 9 Connectivity and 4 Different Packet Streams Supported by WSA5000 Table 7 The Categories of VRT Packet Streams Supported by ThinkRF s WSA5000 Contents Standard Formats Custom Formats Context IF Co...

Страница 29: ...the list of Stream Identifiers used by ThinkRF for different Packet Class Stream Each ID will be mentioned in the subsequent corresponding Packet Class sections Table 8 A List of Stream Identifiers As...

Страница 30: ...words in the entire context packet including all headers the context indicator field and context sections 9 Stream Identifier shall be the 32 bit word 0x90000001 10 Timestamp Integer Seconds shall be...

Страница 31: ...presenting the Stage 1 and Stage 2 gain values The Stage 1 gain represents the amount of gain in the front end system the RF gain The Stage 2 gain represents the amount of gain in the back end system...

Страница 32: ...stamps are in UTC 6 TSF field shall be set to 10 indicating that the fractional part of the timestamp measures real time picosecond resolution 7 Pkt Count shall start at 0000 and increment once for ea...

Страница 33: ...cimation settings that have been enabled The Bandwidth field shall use the 64 bit two s complement format as shown in Table 18 This field has an integer and a fractional part with the radix point to t...

Страница 34: ...of the Reference Level field has a range of nearly 256dBm with a resolution of 1 128dBm 0 0078125dBm For examples a Reference Level field value of 0x0080 represents a reference level of 1dBm 0xFF80 re...

Страница 35: ...t shall rollover to 0000 on the next count 8 Pkt Size indicates the total number of 32 bit words in the entire context packet including all headers the context indicator field and context sections 9 S...

Страница 36: ...o maintain the data output format to always be I Q such that the spectral inversion is not required at the user end during data processing This information however matters only when operating in the Z...

Страница 37: ...fields in an IF Data packet is organized as shown in Table 27 Packets is transmitted in big endian byte order Table 27 IF Data Class Field Values 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14...

Страница 38: ...data payload of an IF Data packet contains a contiguous sequence of the Data Samples from an IF Data Sample stream The number of words in the data payload is variable from packet to packet and can be...

Страница 39: ...ord follows by the second I sample in the lower 16 bit as seen in Table 31 Table 31 I14 Data Payload Arrangement with Upper 2 bit Signed Extended to I16 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16...

Страница 40: ...tor and Enable Bits Enable Bit Position Indicator Bit Position Indicator Name 30 18 Valid Data Indicator 29 17 Reference Lock Indicator 26 14 Spectral Inversion Indicator 25 13 Over range Indicator 24...

Страница 41: ...the settle time is within hundred of nanoseconds Reference Lock 0 One or more PLLs failed to lock Same as 1 above Spectral Inversion 1 Spectral inversion occurs when the frequency of the local oscill...

Страница 42: ...e command structure and syntax using ASCII characters to provide some basic standardization and consistency to the control commands SCPI commands hence lend themselves to communications with equipment...

Страница 43: ...atus register and the error event queue Syntax CLS Parameter Response None ESE ESE ESE command enables bits in the ESE register The decimal integer value entered is the binary equivalent of the desire...

Страница 44: ...Note The model string returned will not include the options ie ELO HIF WBIQ etc To find out which options a model has use SYSTem OPTions command Syntax IDN Parameter None Response Manufacturer Model...

Страница 45: ...the SRE STB register bits mapping Syntax SRE integer SRE Parameter Response integer STB STB Status Byte query returns the decimal sum of the bits set in the STB register without erasing its content T...

Страница 46: ...be stopped The capturing process does not wait until the end of a packet to stop it will stop immediately upon receiving the command Syntax SYSTem ABORt Parameter Response None RST State N A Example...

Страница 47: ...new LAN configuration type to be applied to the WSA This command does not take effect until SYSTem COMMunicate LAN APPLy is sent please refer to the Caution note of the APPLy command Once the option...

Страница 48: ...COMM LAN DNS CURRENT SYSTem COMMunicate LAN GATEway The set command will store the new LAN gateway to be applied to the WSA This command does not take effect until SYSTem COMMunicate LAN APPLy is sent...

Страница 49: ...it is not affected by power on STATus PRESET or RST The query will return the maskaddress set or that of the actual current configuration if one is not issued The CURRENT query will return what is cur...

Страница 50: ...uffer of any data that is waiting to be sent Thus it is recommended that the flush command should be used when switching between different capture modes to clear up the remnants of packet within the W...

Страница 51: ...omatically have the lock The next application will need to perform this query request to attain the lock When there is only one application connected or the last one remained that application will aut...

Страница 52: ...put1 SENSe FREQuency LOSCillator 002 WSA5000 XXX HIF Model INPut MODE HIF SENSe FREQuency IF 003 WSA5000 4XX WBIQ1 Model None OUTput IQ MODE is defaulted to DIGitizer 004 WSA5000 4XX P Model None 1 EL...

Страница 53: ...Tem VERSion Parameter None Response NR2 Output Data Type String decimal number YYYY V Example SYST VERS SYSTem DATE This command set or queries the current date of the WSA5000 When the date is set the...

Страница 54: ...tive to its current time Further information will be provided in a future revision of this document Syntax SYSTem TIME ADJust integer unit SYSTem TIME ADJust Parameters second or sub second unit Allow...

Страница 55: ...ST State DISable Examples SYST TIME SYNC NTP ONCE SYST TIME SYNC DISABLE SYSTEM TIME SYNC SYSTem TIME SYNC STATus This command returns the current status of the time synchronization Further informatio...

Страница 56: ...ecution Error EXE Command Error CME Not Used Power ON PON 0 1 2 3 4 5 6 7 ESR ESE Standard Event Status Register 0 1 2 3 4 5 6 7 N A N A Error Event Queue EAV Questionable Register Message Available M...

Страница 57: ...d refer to Appendix D SCPI Status and Event Registers Caution This query clears all bits in the register to 0 See Figure 13 for the Operation Status register bits mapping Syntax STATus OPERation EVENt...

Страница 58: ...ter Response None STATus QUEStionable EVENt This command queries the standard Questionable Status Register QSR for any event The query returns the decimal sum of the bits set in the QSR The decimal su...

Страница 59: ...desired 16 bit mask to be enabled Bits enabled in this register allow accessing the equivalent bits status in the QSR and QCR registers Bits enabled in QER and set in QSR QCR register will result in t...

Страница 60: ...e This command sets or queries the variable attenuation of the WSA5000 s RFE Note This command applies to WSA5000 408P 418 427 and their variants only For WSA5000 2XX 3XX 408 and their variants see IN...

Страница 61: ...each stage Syntax INPut GAIN Index Boolean INPut GAIN Index Parameter Integer ON OFF 1 0 Input Data Type Integer Character Integer Allowable Values Index Varies depending on the product model For exam...

Страница 62: ...NPUT GAIN HDR 5 INP GAIN HDR 20 dB INP GAIN HDR INPut MODE This command sets or queries the WSA5000 s RFE mode of operation Notes The RFE modes affect the data packing method due to the different outp...

Страница 63: ...the response code 002 When this model is used the INPut MODE command will only take response with the DD and HIF parameters SOURce Commands SOURce REFerence PLL This command selects and queries the 1...

Страница 64: ...ters each type of filters with its own decimator The decimator captures one sample at every integer number of samples The filters are arranged in the following manner For the decimation rate of 4 only...

Страница 65: ...e for HDR receiver mode the frequency resolution is 10Hz without further frequency shifting capability Refer to RF Receiver Front End page 17 for more details For example the system is in ZIF mode to...

Страница 66: ...ntax SENSe FREQuency IF non zero integer Parameters IF index Input Data Type Non zero Integer Allowable Values Varies depending on RFE input mode frequency product model and options Query Response IF...

Страница 67: ...age 17 Syntax SENSe FREQuency SHIFt NRf unit SENSe FREQuency SHIFt MAX MIN Parameters Frequency unit Input Data Type Float character Allowable Values 62 5 62 5MHz Query Response integer Default I O Un...

Страница 68: ...otes When the CONNector option is selected all commands affecting the digitizer data path of the WSA5000 will not apply these include TRACe Commands level triggering TRIGger LEVel and digital signal p...

Страница 69: ...UTput IQ CONNector INVersion NRf unit Parameters Optional center frequency unit Input Data Type Double character Default Input Unit Hz Allowable Values Varies depending on the product model Query Resp...

Страница 70: ...around the SENSe FREQuency CENTer value Refer to the Frequency Domain Triggering section for more information Syntax TRIGger LEVel NRf unit NRf unit NR1 unit TRIGger LEVel Parameters Response start s...

Страница 71: ...Ck DATA is issued the WSA5000 will capture and store the total number of samples into a buffer Hence the samples within a single block capture is continuous from one packet to the other but not necess...

Страница 72: ...d sets or queries the total number of packets set in the WSA The maximum is limited by the storage capacity of a WSA5000 and the samples per packet SPP size set through TRACe SPPacket Therefore when T...

Страница 73: ...SPP is therefore simplified to 65504 or 216 32 for all data format The lower bound of the SPP is limited by the capture engine s minimal transfer requirement of 256 samples Table 37 summarizes the SPP...

Страница 74: ...e command the WSA system will stop when the current capturing VRT packet is completed with the required samples as opposed to SYSTem ABORt Note After this command is issued SYSTem FLUSh command should...

Страница 75: ...cuted During sweeping the WSA internal buffer might be overflown at which point the sweep engine will pause The engine will resume sweeping once there are enough space for the next block of data or mo...

Страница 76: ...ta packets belonging to a new sweep start Even though the start ID value is optional a VRT Extension Context Packet with the New Sweep Start ID page 36 value will always be sent out after this command...

Страница 77: ...figurations under SWEep ENTRy with values from the sweep entry of the specified index No new entry is created until SWEep ENTRy SAVE command is issued and any changes will not affect the existing entr...

Страница 78: ...Examples SWEEP ENTRY NEW SWEep ENTRy READ This query command returns the current configuration settings of a sweep entry Syntax SWEep ENTRy READ integer Parameter Entry index value Input Data Type Int...

Страница 79: ...SAVE integer Parameter Entry index value Input Data Type Integer Allowable Values COUNt value 1 RST State N A Examples SWEEP ENTR SAVE SWE ENTR SAVE 5 SWEep ENTRy ATTenuator Refers to the INPut ATTenu...

Страница 80: ...y CENTer command If a range is not given the step size is ignored Syntax SWEep ENTRy FREQuency STEP NRf unit SWEep ENTRy FREQuency STEP Parameter freq unit Input Data Type Double character Allowable V...

Страница 81: ...infinite dwell time In this case the sweep engine will move on as soon as the current data capture amount has been met as explained in the previous paragraph When the trigger type is NONE dwell time i...

Страница 82: ...ThinkRF s WSAs are network ready devices conveying control commands and data using TCP IP protocol Each WSA receives SCPI commands and sends query responds over port 37001 and sends VRT context and da...

Страница 83: ...addition refer to the Connecting to the WSA5000 of the WSA5000 User Guide v3 6 or later for more information on how to connect to WSA5000 and to determine its IP address ThinkRF WSA5000 Wireless Signa...

Страница 84: ...to determine how to parse the response message Note that the bracket is for clarity of the explanation purpose only not to be included in the message A WSA with the discovery version 2 would respond...

Страница 85: ...ersion but will not respond to variations of either version The interface does not differentiate between upper case and lower case letters but only the long or short form of a command An example corre...

Страница 86: ...used to separate alternative parameter options Means is defined as Parameter types This section defines different SCPI parameter data type Parameter Type Description boolean ON OFF 1 0 Boolean paramet...

Страница 87: ...efault may be specified If units are not specified then the default units apply Note the following examples which are all equivalent Example FREQ CENTer 2441 5 MHz is equivalent to FREQ CENTer 2441500...

Страница 88: ...r query 3 Questionable Register Summary This bit is not used and is always 0 4 Message Available MAV This bit is set if there is any unread data in the Output queue 5 Standard Event Status Bit ESB Thi...

Страница 89: ...register that is used to determine the state of operation It is read by issuing a STATus OPERation EVENt command Bit Name Description 0 3 not used These bits are not used and is always 0 4 Measuring M...

Страница 90: ...ceived that is NOT allowed for the particular command 230 Data corrupt or stale Possibly invalid data new reading started but not completed since last access 240 Hardware error Indicates that a legal...

Страница 91: ...nt Status Register v1 0 IDN Query device identification v1 0 OPC Operation Complete TBD OPC Query OC TBD RST Reset to factory default v1 0 SRE integer Service Request Enable bits v1 0 SRE Query SRE re...

Страница 92: ...ENTer NRf unit Sets the center frequency of the RFE v3 0 CENTer MAX MIN IF non zero integer Queries the IF frequencies that are used for the current input mode and center frequency v4 3 2 LOSCillator...

Страница 93: ...he settings of an existing sweep entry into the current settings for quick editing v3 1 COUNt Gets the number of entries available in the list v3 1 DELETE integer ALL Deletes a specified entry or all...

Страница 94: ...k PACKets page 72 v3 0 PPBlock SPPacket As defined in TRACe SPPacket page 73 v3 0 SPPacket TRIGger LEVel As defined in TRIGger LEVel page 70 v4 1 0 LEVel TYPE As defined in TRIGger TYPE page 69 v3 1 2...

Страница 95: ...the application that has the lock can perform the task v3 0 OPTions Returns comma separated 3 digit values to represent the hardware option s or features available with a particular WSA model v3 2 1 S...

Страница 96: ...am STARt integer Initiates the capture storage and streaming of IQ data v3 1 STOP Stops streaming v3 1 TRIGger Page 69 LEVel NRf unit NRf unit NRf unit start stop level Sets the frequency range and am...

Страница 97: ...ansport VRT Draft Standard VITA 49 0 2007 VITA Standard Organization 31 October 2007 Draft 0 21 http www vita com 3 IEEE Standard Codes Formats Protocols and Common Commands ANSI IEEE Standard 488 2 1...

Страница 98: ...3 2013 Updated this document to correspond with the capabilities of WSA5000 Contact Support for list of changes from WSA4000 to WSA5000 v3 1 October 01 2013 Added OUTput IQ MODE command Table 8 to lis...

Страница 99: ...mands Added New commands SYSTem OPTions and SENSe FREQuency LOSCillator to support WSAs with the external local oscillator mode HDR gain field to SWEep ENTRy READ returned string right after IF gain S...

Страница 100: ...asing on the attenuation setting and removed the mentioning of the dependency on the gain settings v3 3 2 Oct 15 2014 Corrected TRIGger STATus to be unavailable Corrected the absolute power level form...

Страница 101: ...OSCillator information on WBIQ model to Table 2 SENSe DECimation and SYSTem OPTions support or not note on 408P model in INPut ATTenuator VARiable and INPut ATTenuator respectively INPut GAIN command...

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