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lteLayerMap

Layer mapping of modulated and scrambled codewords

Description

example

out = lteLayerMap(in,nu) performs layer mapping of the codeword or codewords, in, onto nu layers. It carries out the layer mapping according to TS 36.211 [1], Sections 5.3.2A and 6.3.3. The function returns an M-by-nu matrix consisting of the modulation symbols for transmission upon nu layers. These transmission layers are formed by multiplexing the modulation symbols from either one or two codewords. The overall operation of the layer mapper is the transpose of that defined in the specification. In other words, the symbols for layers lie in columns rather than rows.

example

out = lteLayerMap(in,nu,txscheme) performs layer mapping using the transmission scheme, txscheme.

out = lteLayerMap(chs,in) performs layer mapping of the codeword or codewords, in, according to the parameters in the channel transmission configuration structure, chs.

Examples

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Map one codeword to four layers for the spatial multiplexing transmission scheme.

When no transmission scheme is specified, the default layer mapping is spatial multiplexing.

out = lteLayerMap(ones(40,1),4);
sizeOut = size(out)
sizeOut = 1×2

    10     4

Map one codeword to four layers for the transmit diversity transmission scheme.

out = lteLayerMap(ones(40,1),4,'TxDiversity');
sizeOut = size(out)
sizeOut = 1×2

    10     4

Input Arguments

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Scrambled and modulated codeword or codewords, specified as a numeric vector or a cell array of numeric vectors. As a cell array, in contains one or two vectors of modulation symbols that result from the scrambling and modulation of DL-SCH or UL-SCH codewords.

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

Data Types: double

PDSCH transmission scheme, specified as one of the following options.

Transmission schemeDescription
'Port0'Single antenna port, port 0
'TxDiversity'Transmit diversity
'CDD'Large delay cyclic delay diversity scheme
'SpatialMux'Closed loop spatial multiplexing
'MultiUser'Multi-user MIMO
'Port5'Single-antenna port, port 5
'Port7-8'Single-antenna port, port 7, when NLayers = 1. Dual layer transmission, ports 7 and 8, when NLayers = 2.
'Port8'Single-antenna port, port 8
'Port7-14'Up to eight layer transmission, ports 7–14

This optional input takes precedence over chs.TxScheme.

Data Types: char | string

Channel-specific transmission configuration, specified as a structure that can contain the following parameter fields.

Parameter FieldRequired or OptionalValuesDescription
NLayersRequired

Integer from 1 to 8

Number of transmission layers.

TxSchemeOptional

'Port0', 'TxDiversity', 'CDD', 'SpatialMux', 'MultiUser', 'Port5', 'Port7-8', 'Port8', 'Port7-14'.

The default TxScheme is 'Port0' for NLayers = 1, and 'SpatialMux' otherwise.

PDSCH transmission scheme, specified as one of the following options.

Transmission schemeDescription
'Port0'Single antenna port, port 0
'TxDiversity'Transmit diversity
'CDD'Large delay cyclic delay diversity scheme
'SpatialMux'Closed loop spatial multiplexing
'MultiUser'Multi-user MIMO
'Port5'Single-antenna port, port 5
'Port7-8'Single-antenna port, port 7, when NLayers = 1. Dual layer transmission, ports 7 and 8, when NLayers = 2.
'Port8'Single-antenna port, port 8
'Port7-14'Up to eight layer transmission, ports 7–14

Output Arguments

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Modulation symbols, returned as a numeric matrix. out is an M-by-nu matrix consisting of M modulation symbols for transmission upon nu layers.

Data Types: double
Complex Number Support: Yes

References

[1] 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