Physical Random Access Channel (PRACH)

The Random Access Channel (RACH) of the common transport channels is mapped onto one or more uplink physical random access channels (PRACH). This allows the capacity of RACH to be flexibly scaled as needed.

Physical Channel Parameters

State

Choice: ON | OFF

Default: ON

Double-click or use the drop-down menu to set the state of the current channel ON or OFF.

Power

Range: –60 to 0 dB

Default: 0 dB

Enter a value to set the current channel power. The CDP graph displays the normalized power of each RU in each timeslot after you generate the waveform. Refer to the Power Setting for the power calculation of the carriers, channels/timeslots and RUs.

Timing Offset

Range: –8 to 8 chips

Default: 0.000 Chips

Enter a value to set the transmit timing offset for the current channel. The cell is active for uplink only.

Timing Offset property is only valid for uplink timeslots. For downlink timeslots, it is read-only. PRACH is always located in uplink timeslots.

Allocated RU number

This cell displays the number of allocated resource units for the current channel.

Payload

Selections: STD, PN9, PN15, User file

Default: STD

Click the icon at the right of the cell to select the data source type.

STD	select standard data encoding, which enables the BCH Parameters Setup
PN9	select random sequence numbers
PN15	select random sequence numbers
User File	selects a user-defined file. When user file is selected as the data type, two new cells are added to the cell format. Click to expand the Payload cell to access the User File cell. Click at the far right of the User File cell and browse to the location of the data file to be used. The Data Length cell is updated with the corresponding length.

Transport Channel Parameters

RACH Parameters Setup

When you select the payload data source as the standard data encoding, RACH parameters are active to be configured.

Payload

Selections: PN9, PN15, 0, 1 text file

Default: PN9

Click the cell and the icon at the far right of the cell to access the data menu.

PN9

select random sequence numbers

PN15

select random sequence numbers

0, 1 text file

select this to load a user-defined 0, 1 text file as the data source. When this is selected as the data type, two new cells are added to the cell format.

Click to expand the cell to access the User File cell.
Click at the far right of the User File cell. An Open window is displayed for navigating to and selecting the desired ASCII file (*.txt). The Data Length cell is updated with the corresponding length.

Block Size

Range: 0 to 5000.

Default: 20

Set the block size (information data) of the channel.

Number of Blocks

Range: 1 to 512

Default: 1

View the number of blocks of the current channel as specified in the standards for the channel depending on the link direction.

CRC Size

View the CRC size as specified for the channel.

Coding Type

View the coding type as specified for the channel.

TTI

View the TTI length (ms) as specified for the channel.

Rate Matching Attribute

View the rate matching attribute to be used in coding the RACH.

Radio Frame Segment Output

View the radio frame segment output (bits) that depends on the currently configured channel information.

Puncture Ratio

View the configured puncture ratio of the current channel that depends on the block size and rate matching attribute of the channel.

Second Interleaver Type

View the second interleaver type of the current channel which is fixed at Frame Related.

Bit Per Frame

View the bits per frame of the current channel that depends on the currently configured channel information.

Data Rate

View the data rate of the current channel.

Resource Unit Setup

The Resource Unit Setup table enables you to configure the resource unit for each channel.