lteSCIEncode

SCI encoding

Syntax

cw = lteSCIEncode(ue,scibits)

cw = lteSCIEncode(ue,scibits,outlen)

Description

cw = lteSCIEncode(ue,scibits) returns the codeword resulting from the sidelink control information (SCI) encoding of the input bit vector, scibits, given the field settings in the user equipment structure, ue. As defined in TS 36.212 [1], Section 5.4.3, the encoding process includes 16 bit CRC attachment, tail biting convolutional coding, rate matching and PUSCH interleaving. This processing takes in an SCI message generated with lteSCI. The codeword returned is ready for transmission on the ltePSCCH physical channel.

cw = lteSCIEncode(ue,scibits,outlen) rate matches the returned codeword to the output length provided by outlen.

Examples

Encode Format 0 SCI Message

Create an SCI format 0 message structure, modify selected information field values, and generate the new SCI message and payload bits. Encode the SCI message payload bits.

Create a UE settings structure and SCI message structure.

ue = struct('NSLRB',50,'CyclicPrefixSL','Normal');
sci0 = lteSCI(ue);

Modify the SCI message structure settings and generate an SCI message bit vector.

sci0.FreqHopping = 1;
sci0.ModCoding = 3;
[sci0,scibits] = lteSCI(ue,sci0);

Generate an encoded SCI message codeword.

cw = lteSCIEncode(ue,scibits);

Encode Format 0 SCI Message of Specified Length

Create an SCI format 0 message structure, and generate the new SCI message and payload bits. Encode the SCI message payload bits in a codeword of length specified by outlen.

Create a UE settings structure and SCI message structure.

ue = struct('NSLRB',50,'CyclicPrefixSL','Extended');
[sci0,scibits] = lteSCI(ue);

Generate an encoded SCI message codeword of length specified by outlen.

outlen = 144;
cw = lteSCIEncode(ue,scibits,outlen);
size(cw)

ans = 1×2

   144     1

Input Arguments

ue — User equipment settings

structure

User equipment settings, specified as a structure containing this parameter field:

SidelinkMode — Sidelink mode

'D2D' (default) | 'V2X' | optional

Sidelink mode, specified as 'D2D' or 'V2X'.

Data Types: char | string

CyclicPrefixSL — Cyclic prefix length

'Normal' (default) | 'Extended' | optional

Cyclic prefix length, specified as 'Normal' or 'Extended'.

Data Types: char | string

Data Types: struct

scibits — SCI message bit vector

column vector

SCI message bit vector, specified as a column vector. scibits are the SCI processing input bits to be transmitted on a single PSCCH.

Data Types: double | int8

outlen — Codeword length

nonnegative integer | optional

Codeword length, specified as a nonnegative integer. outlen must be a multiple of 2. It should be a multiple of 12 for D2D normal cyclic prefix and a multiple of 10 for extended cyclic prefix and V2X. The output length is meant to match the number of data-carrying SC-FDMA symbols in a PSCCH subframe and align with the dimensions of the PUSCH interleaver stage.

Output Arguments

cw — Codeword

288 bit or 240 bit column vector | column vector with zero rows | column vector with length equal to outlen

Codeword resulting from SCI processing, returned as a column vector of binary values. cw is the result of SCI processing the input vector, scibits. The output codeword matches the normal or extended cyclic prefix bit capacity available in the ltePSCCHIndices output, not accounting for the sidelink SC-FDMA guard symbol. Depending on the function syntax used and input configuration, the length of cw is:

• 288 bits for nonempty data input and normal cyclic prefix

• 240 bits for nonempty data input and extended cyclic prefix and for V2X

• An empty 0-by-1 matrix for an empty data input

• Rate-matched to outlen

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 R2016b