docsIf31CmUsOfdmaChanCyclicPrefix
DOCS-IF31-MIB ·
.1.3.6.1.4.1.4491.2.1.28.1.13.1.7
Object
column
number of samples UsOfdmaCyclicPrefix
Cyclic prefix is added in order to enable the receiver to overcome the effects of inter-symbol interference (ISI) and inter-carrier interference caused by microreflections in the channel. The cyclic prefix (in usec) is converted into samples using the sample rate of 102.4 Msamples/s. There are eleven values for the length of the CP and the choice depends on the delay spread of the channel; a longer delay spread requires a longer cyclic prefix.
Context
- MIB
- DOCS-IF31-MIB
- OID
.1.3.6.1.4.1.4491.2.1.28.1.13.1.7- Type
- column
- Access
- readonly
- Status
- current
- Units
- number of samples
- Parent
- docsIf31CmUsOfdmaChanEntry
- Table
- docsIf31CmUsOfdmaChanTable
- Siblings
- 10
Syntax
number of samples UsOfdmaCyclicPrefix
- Source
- UsOfdmaCyclicPrefix
- Base type
Unsigned32
Values & Constraints
Type Constraints
range: 96
range: 128
range: 160
range: 192
range: 224
range: 256
range: 288
range: 320
range: 384
range: 512
range: 640
Related Objects
Sibling Objects
| Object | Type | Syntax | OID |
|---|---|---|---|
| docsIf31CmUsOfdmaChanConfigChangeCt This attribute contains the value of the Configuration Change
Count field in the Upstream Channel Descriptor (UCD) MAC
Management Message corresponding to this OFDMA channel. | column | Unsigned32 | .1.3.6.1.4.1.4491.2.1.28.1.13.1.1 |
| docsIf31CmUsOfdmaChanTxPower This attribute represents the operational transmit power for
the associated OFDMA upstream channel. | column | dBmV DOCS-IF-MIBTenthdBmV | .1.3.6.1.4.1.4491.2.1.28.1.13.1.10 |
| docsIf31CmUsOfdmaChanPreEqEnabled This attribute defines whether pre-equalization is enabled on
the associated OFDMA upstream channel. | column | SNMPv2-TCTruthValue | .1.3.6.1.4.1.4491.2.1.28.1.13.1.11 |
| docsIf31CmUsOfdmaChanSubcarrierZeroFreq This attribute defines the lower edge frequency of the OFDMA
upstream channel | column | Hz SNMPv2-SMIUnsigned32 | .1.3.6.1.4.1.4491.2.1.28.1.13.1.2 |
| docsIf31CmUsOfdmaChanFirstActiveSubcarrierNum This attribute defines the upper edge of the OFDMA upstream
channel. The minimum channel width for an OFDMA upstream
channel is 6.4 MHz in 4K mode and 10MHz in 2K mode. The valid
… | column | SNMPv2-SMIUnsigned32 | .1.3.6.1.4.1.4491.2.1.28.1.13.1.3 |
| docsIf31CmUsOfdmaChanLastActiveSubcarrierNum This attribute defines the last active subcarrier number.
The valid range is 74 to 3947. | column | SNMPv2-SMIUnsigned32 | .1.3.6.1.4.1.4491.2.1.28.1.13.1.4 |
| docsIf31CmUsOfdmaChanNumActiveSubcarriers This attribute defines the number of active subcarriers within
the OFDMA upstream channel. The valid range is 1 to 3800. | column | SNMPv2-SMIUnsigned32 | .1.3.6.1.4.1.4491.2.1.28.1.13.1.5 |
| docsIf31CmUsOfdmaChanSubcarrierSpacing This attribute defines the subcarrier spacing associated with
a particular FFT mode configured on the OFDMA upstream
channel. If it is 2K mode, then the subcarrier spacing is 50kH… | column | kHz SubcarrierSpacingType | .1.3.6.1.4.1.4491.2.1.28.1.13.1.6 |
| docsIf31CmUsOfdmaChanRollOffPeriod Windowing is applied in order to maximize channel capacity
by sharpening the edges of the spectrum of the OFDMA signal.
Windowing is applied in the time domain by tapering (or
rol… | column | number of samples UsOfdmaRollOffPeriod | .1.3.6.1.4.1.4491.2.1.28.1.13.1.8 |
| docsIf31CmUsOfdmaChanNumSymbolsPerFrame This attribute is the number of symbol periods per frame.
For channel bandwidth greater than 72MHz, the maximum number
of symbol periods per frame is 18 for 2K mode and 9 for 4K
m… | column | SNMPv2-SMIUnsigned32 | .1.3.6.1.4.1.4491.2.1.28.1.13.1.9 |