lteCSICodebook

Codebook for channel state information reporting

Syntax

out = lteCSICodebook(nu,p,idx)

out = lteCSICodebook(nu,p,idx,table)

out = lteCSICodebook(nu,p,i1,i2)

Description

out = lteCSICodebook(nu,p,idx) returns the precoding matrix associated with channel state information (CSI) reporting as defined in TS 36.213 [1], Section 7.2.4 given the number of layers, nu, the number of antennas, p, and the codebook index, idx. For more information, see CSI Codebook Reporting and ltePMIInfo.

out = lteCSICodebook(nu,p,idx,table) where table specifies the codebook selection table. For more information, see CSI Codebook Reporting.

out = lteCSICodebook(nu,p,i1,i2) where i1 and i2 specify the first and second codebook indices, respectively. This signature was only intended for p = 8. This signature may be removed in a future release, instead use out = lteCSICodebook(nu,p,idx) with idx = [i1 i2].

Examples

Create Codebook Entry for CSI Reporting

This example creates a codebook entry for CSI reporting with 2 layers, 4 antennas, and a codebook index of 3.

lteCSICodebook(2,4,3)

ans = 4×2 complex

   0.3536 + 0.0000i   0.0000 + 0.3536i
   0.0000 - 0.3536i   0.3536 + 0.0000i
  -0.3536 + 0.0000i   0.0000 + 0.3536i
   0.0000 + 0.3536i   0.3536 + 0.0000i

Create Alternate Codebook Entry for CSI Reporting

Create an alternative codebook entry for CSI reporting with three layers, and four antennas, using codebook indices provided.

lteCSICodebook(3,4,[0 7],'AltCodeBook4Tx')

ans = 4×3 complex

   0.2887 + 0.0000i   0.0000 + 0.2887i  -0.2041 + 0.2041i
   0.2041 - 0.2041i  -0.2041 - 0.2041i   0.0000 - 0.2887i
   0.0000 - 0.2887i   0.2887 + 0.0000i  -0.2041 - 0.2041i
  -0.2041 - 0.2041i  -0.2041 + 0.2041i   0.2887 + 0.0000i

The codebook entry [i1 i2] = [0 7] from TS 36.213, Table 7.2.4-0C is used.

Input Arguments

nu — Number of transmission layers

1,...,8 | positive scalar integer

Number of transmission layers, specified as an integer from 1 to 8.

p — Number of transmission antennas

1 | 2 | 4 | 8 | positive scalar integer

Number of transmission antennas, specified as 1, 2, 4, or 8.

idx — Codebook index

0,...,15 | scalar integer | vector with two integers

Codebook index, specified as an integer or vector of two integers from 0 to 15.

• If p = 8, idx should be a pair of indices [i1 i2].

• If p = 4 and table = 'AltCodebook4Tx', idx should be a pair of indices [i1 i2].

• If p = 4 and table = 'StdCodebook4Tx', idx should be a single index or a pair with i1 set to zero.

• If p = 1 or p = 2, idx should be a single index or a pair with i1 set to zero.

For more information, see CSI Codebook Reporting.

Example: [0 3] indicates the codebook indices [i1 i2].

i1 — First codebook index

0 (default),...,15 | scalar integer

First codebook index, specified as an integer from 0 to 15. For more information, see CSI Codebook Reporting.

i2 — Second codebook index

0,...,15 | scalar integer

Second codebook index, specified as an integer from 0 to 15. For more information, see CSI Codebook Reporting.

table — Codebook selection table

‘StdCodebook4Tx’ (default) | ‘AltCodebook4Tx’ | optional

Codebook selection table for four transmission antennas, specified as 'StdCodebook4Tx' or 'AltCodebook4Tx'. table is optional and only applicable when p = 4. For more information, see CSI Codebook Reporting.

Data Types: char | string

Output Arguments

out — Precoding matrix associated with CSI reporting

complex-valued numeric matrix

Precoding matrix associated with CSI reporting, returned as a complex-valued numeric p-by-nu matrix, where p is the number of transmission antennas, and nu is the number of transmission layers. nu must always be less than or equal to p. For more information, see CSI Codebook Reporting.

Data Types: double
Complex Number Support: Yes

More About

CSI Codebook Reporting

A UE reports the precoding matrix indicator (PMI) according to the feedback modes as described in TS 36.213 [1], Section 7.2.4. lteCSICodebook returns the precoding matrix for CSI reporting as a p-by-nu matrix, where p is the number of transmission antennas (CSI-RS or CRS ports) and nu is the number of transmission layers (PDSCH transmission layers). nu must always be less than or equal to p. Inputs to the function are nu, p, idx indicating the codebook indices, and optionally table indicating the codebook selection table.

Reference Signal	Codebook	Number of layers, nu	p	Codebook indices, idx (See Note 1)		table	Transmission scheme
				i1	i2
CSIRefP	TS 36.213, Table 7.2.4-1	1	8	0–15	0–15	n/a	'Port7-14'
	TS 36.213, Table 7.2.4-2	2
	TS 36.213, Table 7.2.4-3	3		0–3
	TS 36.213, Table 7.2.4-4	4			0–7
	TS 36.213, Table 7.2.4-5	5			0
	TS 36.213, Table 7.2.4-6	6
	TS 36.213, Table 7.2.4-7	7
	TS 36.213, Table 7.2.4-8	8		0
CellRefP or CSIRefP (See Note 2)	TS 36.213, Table 7.2.4-0A	1	4	0–15	0–15	'AltCodebook4Tx'	'Port7-8' or 'Port7-14' (See Note 2)
	TS 36.213, Table 7.2.4-0B	2
	TS 36.213, Table 7.2.4-0C	3		0
	TS 36.213, Table 7.2.4-0D	4
	TS 36.211, Table 6.3.4.2.3-2	1–4	4	0	0–15	'StdCodebook4Tx'
	TS 36.211, Table 6.3.4.2.3-1	1	2		0–3	n/a
		2			0–2
	Precoding matrix = 1	1	1		0		any single antenna
Note Preferred format for codebook indices, idx, is a two element vector, [i1 i2]. A scalar format is accepted when the only available setting for i1 is zero. For this case, use the applicable scalar input range shown for i2. CellRefP for the 'Port7-8' or CSIRefP for the 'Port7-14'

References

[1] 3GPP TS 36.213. “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network. URL: https://www.3gpp.org.

[2] 3GPP TS 36.211. “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network. URL: https://www.3gpp.org.

Version History

Introduced in R2014a