Configuration (Custom OFDM)

Menu Path: MeasSetup > Custom OFDM Properties... > Frame Definition tab

Configuration contains parameters that specify the allocation's name, type, power boost and payload.

Enabled enables or disables the analysis of an allocation. At least one is always enabled. If you try to disable all of them, the first allocation will be automatically enabled.

Name sets name of the selected allocation (limited to 30 characters).

Type selects the allocation type. The allocation type is also selectable in the Type column of the Allocation Summary.

• Preamble- configures the allocation as a preamble. Preamble allocations are used for initial sync and channel estimation.
• Data- configures the allocation as data. Data allocations carry data payload.
• Pilot- configures the allocation as a pilot. Pilot allocations are typically interspersed within the data and are used for tracking and updating channel estimation.
• Idle- configures the allocation as idle. Idle allocations are the off, or ignored, portion of the frame.

Default: Data

Range: Preamble, Data, Pilot, Idle

Power Boost sets the relative power boosting (dB) of this allocation relative to the other allocations.

All constellations are normalized to the same RMS power, so absolute power of the 0 dB level is set to the measured RMS average of all allocations whose PowerBoostLevel is 0 dB.

Default: 0

Payload - These parameters define the allocation's payload:

Sequence specifies the allocation's PN 1) part number, or 2) packet number sequence.

• Unknown - specifies that the payload is unknown (known modulation). Only Unknown is supported for Data allocations.
• PN9 - specifies a PN9 bit sequence, as specified in CCITT T-REC-O.153.
• PN11 - specifies a PN11 bit sequence, as specified in CCITT T-REC-O.153.
• PN15 - specifies a PN15 bit sequence, as specified in CCITT T-REC-O.151.
• PN20 - specifies a PN20 bit sequence, as specified in CCITT T-REC-O.153.
• PN23 - specifies a PN23 bit sequence, as specified in CCITT T-REC-O.151.
• Custom - specifies a custom sequence.

Default: PN23

Custom Sequence Type (only supported for Preamble/Pilots) specifies the type of custom sequence when Sequence is set to Custom. After selecting the Custom Sequence Type, enter or paste the sequence into the field below the Modulation parameter, making sure the entered data matches the specified type. Custom sequences are loaded onto the subcarriers starting with the lowest subcarrier and continuing to the highest subcarrier, then to the next symbol starting at the lowest subcarrier, etc.

• Bit Sequence- Bit Sequence is a list of digits (0 or 1) that can be separated by comma, NewLine or no space.

  BPSK Binary phase shift keying - A type of phase modulation using 2 distinct carrier phases to signal ones and zeros. mapping table:

  Bits	BPSK Symbol (I, Q)	Symbol Index
  0	(1.0, 0)	0
  1	(-1.0, 0)	1

  QPSK Quadrature phase shift keying mapping table:

  Bits (MSB Most significant bit. In a binary coding scheme, the bit having the greatest numerical value. Analogous to the left-most numeric position in a decimal number., LSB Least Significant Bit: In a binary coding scheme, the bit having the least numerical value. Analogous to the units position in a decimal number.)	QPSK Symbol (I, Q)	Symbol Index
  (0,0)	(0.707,0.707)	0
  (1,0)	(0.707, -0.707)	2
  (1,1)	(-0.707,-0.707)	3
  (0,1)	(-0.707,0.707)	1

  Example:

  If the bit sequence in the file is: 001011101011…

  • For BPSK, bits are mapped to symbol indexes: 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, …
  • For QPSK, bits are separated into groups 00,10,11,10,10,11, and they are mapped to symbol indexes: 0, 2, 3, 2, 2, 3, ...

• IQ Symbol Sequence- IQ Symbol Sequence is a comma or NewLine separated list of interleaved real and imaginary values, representing the IQ symbols in the allocation payload.

Modulation selects the allocation's modulation format. The modulation is also selectable in the Modulation column of the Allocation Summary.

• Unknown - the allocation's modulation format is unknown and autodetection will be attempted.
• BPSK- the allocation uses a BPSK modulation format.
• QPSK- the allocation uses a QPSK modulation format.
• 8-PSK Phase Shift Keying: A broad classification of modulation techniques where the information to be transmitted is contained in the phase of the carrier wave.- (data allocations only) the allocation uses an 8-PSK modulation format.
• 16-QAM Quadrature Amplitude Modulation- (data allocations only) the allocation uses a 16-QAM modulation format.
• 32-QAM- (data allocations only) the allocation uses a 32-QAM modulation format.
• 64-QAM- (data allocations only) the allocation uses a 64-QAM modulation format.
• 128-QAM- (data allocations only) the allocation uses a 128-QAM modulation format.
• 256-QAM- (data allocations only) the allocation uses a 256-QAM modulation format.
• 512-QAM- (data allocations only) the allocation uses a 512-QAM modulation format.
• 1024-QAM- (data allocations only) the allocation uses a 1024-QAM modulation format.
• 2048-QAM- (data allocations only) the allocation uses a 2048-QAM modulation format.
• 4096-QAM- (data allocations only) the allocation uses a 4096-QAM modulation format.
• 8192-QAM- (data allocations only) the allocation uses a 8192-QAM modulation format.
• 16384-QAM- (data allocations only) the allocation uses a 16384-QAM modulation format.

Default: BPSK

See Also

Frame Definition Tab

Custom OFDM Properties Dialog Box