Specifies the mapping matrix type for mapping space-time streams to transmit channels as defined in section 20.3.11.10.1 of IEEE Standard 802.11n-2009.

Note If you set the Mapping Matrix Type property to values other than Direct, the number of transmit channels must be greater than or equal to the sum of the number of space-time streams and the Number of Extension Spatial Streams property if the Standard property is set to 80211N MIMOOFDM.

The default value is Direct.

If you set the Standard property to 80211AX MIMOOFDM or 80211BE MIMOOFDM and the PPDU Type property to Trigger-Based PPDU, the N STS value is dependent on the Spatial Mapping Mode property.

Spatial Mapping Mode property value N_STS value
Common Maximum number of space time streams across Resource Units (RUs)
User Specific Number of space time streams for the specified user

You must use the following active channel string formats when you set the Standard property to 80211AX MIMOOFDM or 80211BE MIMOOFDM and the PPDU Type property to Trigger-Based PPDU.

Spatial Mapping Mode property value Active channel string format
Common "" (empty string)
User Specific "userx"

Remarks

The following table lists the characteristics of this property.

Short Name Mapping Matrix Type
Data type ci32.png
Permissions Read/Write
High-level VIs niWLANG Set Mapping Matrix Type
Resettable No
Direct 0

Specifies direct mapping is used for space-time streams.

For direct mapping matrices NTx must be equal to NSTS . A direct mapping matrix is derived by taking the subset NSTS  *  NSTS of the 8 × 8 identity matrix.

where NTx is the number of transmit channels specified by the Number of Transmit Channels property.
NSTS is the number of space-time streams. If the Standard property is set to 80211N MIMOOFDM, the value of NSTS is determined by the MCS index and the STBC index

The following matrix is an example of a 4 × 4 identity matrix.
Hadamard 1

Specifies Hadamard mapping is used for space-time streams and the extension spatial streams.

The Hadamard mapping matrix is of size NTx * (NSTS + NESS ), where NTx >= (NSTS + NESS ) if the Standard property is set to 80211N MIMOOFDM.

The Hadamard mapping matrix is of size NTx *(NSTS ), where NTx >= NSTS if the Standard property is set to 80211AC MIMOOFDM, 80211AH MIMOOFDM, 80211AX MIMOOFDM, or 80211BE MIMOOFDM.

The Hadamard mapping matrix is derived by taking subset of the 8 × 8 Hadamard matrix.

where NTx is the number of transmit channels specified by the Number of Transmit Channels property.
NSTS is the number of space-time streams. If the Standard property is set to 80211N MIMOOFDM, the value of NSTS is determined by the MCS index and the STBC index.
NESS is the number of extension spatial streams

The following matrix is an example of a 4 × 4 Hadamard matrix.
Fourier 2

Specifies Fourier mapping is used for space-time streams and the extension spatial streams.

The Fourier mapping matrix is given by the following equation:

where n= 0... (N - 1)
N = NTx , where NTx is the number of transmit channels specified by the Number of Transmit Channels property.
k = 0...((NSTS + NESS ) -1) if the Standard property is set to 80211N MIMOOFDM, or k = 0...(NSTS - 1) if the Standard property is set to 80211AC MIMOOFDM, 80211AH MIMOOFDM, 80211AX MIMOOFDM, or 80211BE MIMOOFDM, NSTS is the number of space-time streams. If the Standard property is set to 80211N MIMOOFDM, the value of NSTS is determined by the MCS index and the STBC index. NESS is the number of extension spatial streams.

The following matrices are examples of 2 × 2, 3 × 3, and 4 × 4 matrices.
User Defined 3

Specifies a user-defined mapping for space-time streams and extension spatial streams. You can set this matrix using the niWLANG Set Mapping Matrix VI.