VITA 49, VITA 49A and VITA 49.2
Sharing Data With Other Applications
You can recall recordings in *.vita49 format, allowing you to share recordings between the VSA software and other programs that support VITA 49, VITA 49A and VITA 49.2 files. VITA 49 is a packet-based protocol to convey digitized signal data and metadata (or context data) pertaining to different reference points within a radio receiver.
Supported Payload Format Types
Data format
The VSA software supports the VITA 49.2 data format. In the Packet Header (shown below), bit 25 indicates the data format. This bit is set to "0" for data format 49.0 and "1" for data format 49.2.
Packet Types
The VSA software supports three types of packets: Signal Data Packet without Stream Identifier, Signal Data Packet with Stream Identifier, and Context Packet. The VSA software ignores the stream identifier in the packets, so all signal data packets in the file will be treated as if they don't have a stream identifier.
| Packet Type Bits (31-28) | Supported by VSA | Description | |
| 0000 | YES | Signal Data Packet without Stream Identifier | |
| 0001 | YES (Stream Identifier ignored) | Signal Data Packet with Stream Identifier | |
| 0010 | NO | Extension Data Packet without Stream Identifier | |
| 0011 | NO | Extension Data Packet with Stream Identifier | |
| 0100 | YES | Context Packet |
Signal Data Packets
Signal Data Packets (Type 0000 or 0001) are indicated as either Time Data (0) or Spectrum Data (1) by bit 24 of the Data Header. The VSA software will recall data payload in Time Data packets only.
Supported Payload Format Types
For supported payload format types in VSA, please check the sections below:
VITA 49.0 (49/49A) and VITA 49.2 Payload Formats
For VITA 49, VITA 49A and VITA 49.2, payload types are defined in context packets.
Within the context packet (shown below), bit 15 needs to be set to 1.
If Signal Data Packet Payload Format exists (bit 15 = 1), we can get detailed info from the Data Packet Payload Format Field (in Context packet).
The VSA software has the following Data Packet Payload Format Field requirements:
-
Real/Complex (bits 30, 29) value needs to be 01 (Complex Cartisan)
-
The following combinations are supported for Data Item Format and Data Item Size:
VITA 49.0 (49/49A)
Data Item Format Data Item Size SignedFixedPoint
4-15*, 16
SinglePrecisionFloatingPoint
32
*Data Item Size of 4 through 15 are additionally supported when the Item Packing Field Size is the same as the Data Item Size and when the Packing Method is Link Efficient. The 16 bit Data Item Size does not have these dependencies.
VITA 49.2
Data Item Format Data Item Size Packing Field Size SignedFixedPoint
16
16
SignedFixedPoint
32
32
SinglePrecisionFloatingPoint
32
32
SignedFixedPointNonNormalized
16
16
ODI Payload Format
For ODI, payload type information is taken from the ClassId part in the Data packet. A file is treated as an ODI file if the OUI field ClassId in the Data packets is AXLe = 245CCB or Keysight = 800902 (see ODI ClassId definition below).
The VSA software processes ODI data packets whose fields in the ClassId satisfy the following requirements:
| ODI ClassId Field | Value | |
|
Pad Bit Count |
00000 |
|
|
Reserved |
000 |
|
|
OUI |
0x245CCB for AXIe-defined formats 0x800902 for Keysight-defined formats |
|
|
Pad Word Count |
0000 |
|
|
ODI Reserved |
00 |
|
|
Fixed Value |
00 |
|
|
Event |
00 = none |
|
|
R/C |
01 = Complex IQ |
|
|
Data Type |
0011 000= 16-bit Signed Fixed Point 0100 000= 32-bit Signed Fixed Point |
|
|
Vector Size |
0 0000 0000 0000 for one channel |
Context Packets
The VSA software looks for information in the Context packet to be able to process and show data correctly. See Table 9.1-1 of the VITA 49 standard to see the full Context/Command Indicator Field (CIF Common Intermediate Format: A video image format using 352 horizontal pixels and 288 vertical lines. The format is adopted in multimedia communication standards.) matrix and bit assignments.
For VITA 49.2, Signal Data Packet Payload Format (Bit 15) needs to be set to 1.
For both VITA 49.2 and ODI, the VSA software acts on CIF 0 fields as described in the following table:
| Bit | CIF0 | Conditions | |
|
21 |
Sample Rate |
If set to 1, use it directly in VSA. If set to 0, but if Bandwidth is set to 1, use Bandwidth to make the best guess. If both Sample Rate and Bandwidth are set to 0, use default value 1 as Sample Rate. |
|
|
29 |
Bandwidth |
See Bit 21 Sample Rate. |
|
|
24 |
Reference Level |
If set to 1, use it in VSA to calculate the input range and scaling factor if it's normalized data. |
|
|
27 |
RF Radio Frequency: A generic term for radio-based technologies, operating between the Low Frequency range (30k Hz) and the Extra High Frequency range (300 GHz). Reference Frequency |
If set to 1, then use it as the input center in VSA. |
|
|
26 |
RF Reference Frequency Offset |
If set to 1, check if the value of RF Reference Frequency Offset is 0, if it is 0 then report an error. We don't support offset whose value is not 0 in this version of VSA. |
Other Considerations
- Data files must have at least one context packet and one data packet containing time domain data in the file.
- All packets are contiguous in time (no gaps).
- Context packet type should be distinct (no two context packets with different values exist in the same file, or the first context packet will be used).
- Single channel data only.
- The payload size must be the same for all data packets, except if sampleFrameIndicator in the trailer part of the last packet is defined as FinalPacket.
See Also
