LTE RIV Calculator: RB to RIV and RIV to RB Conversion

This page provides information about the LTE RIV calculator, including how to convert between Resource Blocks (RB) and Resource Indication Value (RIV). It covers both LTE RB to RIV conversion and RIV to RB conversion.

The LTE RIV calculator performs the conversion between the number of RBs, the starting RB, and the RIV.

NOTE:

• The calculator can be used for both uplink and downlink.
• For downlink RIV calculation, enter the number of allocated RBs from 1 to 100.
• For uplink RIV calculation, enter a number from the following array: [2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 25, 27, 30, 32, 36, 40, 45, 48, 50, 54, 60, 64, 72, 75, 80, 81, 90, 96]

LTE RIV Calculator and Examples

EXAMPLE #1:

• INPUTS:
  • LTE Channel Bandwidth = 5 MHz (i.e., Total (N_RB)^DL = 25 RBs)
  • Start RB = 0
  • Number of continuous allocated RBs = 10
• OUTPUT:
  • RIV (Resource Indication Value) = 225

EXAMPLE #2:

• INPUTS:
  • LTE Channel Bandwidth = 5 MHz (i.e., Total (N_RB)^DL = 25 RBs)
  • Start RB = 0
  • Number of continuous allocated RBs = 15
• OUTPUT:
  • RIV (Resource Indication Value) = 299

Formula Used in LTE RIV Calculator for RB to RIV Conversion

The following equations/formula are used in this LTE RIV calculator, which helps in RB to RIV conversion and vice versa for both downlink and uplink directions.

Where:

• (N_RB)^DL for downlink = Number of total RBs as per BW
• L_CRBs = Allocated continuous resource blocks
• RB_start = Starting RB
• RIV = Resource Indication Value

Please note the calculator automatically takes the appropriate (N_RB)^DL based on the channel Bandwidth entered by the user.

• (N_RB)^DL = 6 for 1.4 MHz
• (N_RB)^DL = 15 for 3 MHz
• (N_RB)^DL = 25 for 5 MHz
• (N_RB)^DL = 50 for 10 MHz
• (N_RB)^DL = 75 for 15 MHz
• (N_RB)^DL = 100 for 20 MHz

The RIV stands for Resource Indication Value. In LTE technology, it is the number used to specify PDSCH/PUSCH allocation. It can be used for both downlink type-2 (DCI formats 1A, 1B, 1D) and uplink type-2.

RIV to RB Conversion

• Following steps can be followed for RIV to RB conversion.
• (N_RB)^DL and RB_start can be calculated from the RIV value.
• This is done by applying all possible values of (N_RB)^DL and RB_start and checking whether these values can satisfy either equation 1 or 2 (shown in the image above).
• Once the values satisfy any one of the equations, they are taken as the appropriate conversion for the entered RIV value.

Reference: 3GPP TS 36.213-8.1.1