# lteRIEncode

Rank indication channel encoding

## Description

returns the coded rank indication (RI) bits after performing block coding, as
defined for RI in TS 36.212 [1], Section 5.2.2.6.
`out`

= lteRIEncode(`chs`

,`in`

)`in`

is a vector or cell array containing the RI bits to be
encoded. `out`

contains the encoded bits in the same form.

Multiple codewords can be parameterized by two different forms
of the `chs`

structure. Each codeword can be defined
by separate elements of a 1-by-2 structure array, or the codeword
parameters can be combined together in the fields of a single scalar,
or 1-by-1, structure. Any scalar field values apply to both codewords
and a scalar `NLayers`

is the total number. See UL-SCH Parameterization for
further details.

Since the RI bits are carried on all defined codewords, a single input will result in a cell array of encoded outputs if multiple codewords are parameterized. This allows for easy integration with the other functions.

The RI coder performs different types of block coding depending
upon the number of RI bits in vector `in`

. If `in`

consists
of one element, it uses TS 36.212 [1], Table 5.2.2.6-3. If `in`

consists
of two elements, it uses TS 36.212 [1], Table 5.2.2.6-4 for encoding. The placeholder
bits, *x* and *y* in the tables,
are represented by –1 and –2, respectively.

Similarly, for 3 to 11 bits, the RI encoding is performed as per TS 36.212 [1], Section 5.2.2.6.4. For between 12 and 22 bits, the encoding
is performed as described in TS 36.212, Section 5.2.2.6.5. For more than 22 bits,
the RI coder performs the procedure described in Section 5.2.2.6, which consists of
8-bit CRC attachment, tail-biting convolutional coding, and rate matching to the
output length deduced from the `QdRI`

and
`Modulation`

parameters in `chs`

.

## Examples

## Input Arguments

## Output Arguments

## References

[1] 3GPP TS 36.212. “Evolved Universal Terrestrial Radio Access
(E-UTRA); Multiplexing and channel coding.” *3rd Generation Partnership
Project; Technical Specification Group Radio Access Network*. URL: https://www.3gpp.org.

## Version History

**Introduced in R2014a**

## See Also

`lteRIDecode`

| `lteACKEncode`

| `lteCQIEncode`

| `lteULSCHInterleave`

| `lteULSCH`