wlanSegmentParseBits

Segment-parse data bits

Syntax

y = wlanSegmentParseBits(bits,cbw,numES,numCBPS,numBPSCS)

Description

y = wlanSegmentParseBits(bits,cbw,numES,numCBPS,numBPSCS) performs segment parsing on the input bits as per IEEE^® 802.11™-2020, Section 21.3.10.7, when cbw is 'CBW16' or 'CBW160'.

Note

Segment parsing of the bits applies only when the channel bandwidth is either 16 MHz or 160 MHz, and is bypassed for the remaining channel bandwidths (as stated in the aforementioned section of IEEE 802.11-2020). Therefore, when cbw is any accepted value other than 'CBW16' or 'CBW160', wlanSegmentParseBits returns the input unchanged.

Examples

Segment-Parse Bits in Two OFDM Symbols

Segment-parse coded bits for a VHT configuration (with a channel bandwidth of 160 MHz and three spatial streams) into two OFDM symbols.

Define the input parameters. Set the channel bandwidth to 160 MHz, the number of coded bits per OFDM symbol to 2808, the number of spatial streams to 3, the number of encoded streams to 1, the number of coded bits per subcarrier per spatial stream to 2, and the number of OFDM symbols to 2. Calculate the number of coded bits per OFDM symbol per spatial stream by dividing the number of coded bits per OFDM symbol by the number of spatial streams.

chanBW = 'CBW160';
numCBPS = 2808;
numSS = 3;
numES = 1;
numBPSCS = 2;
numSym = 2;
numCBPSS = numCBPS/numSS;

Create the input sequence of bits.

bits = randi([0 1],numCBPSS*numSym,numSS,'int8');

Perform segment parsing on the bits.

parsedBits = wlanSegmentParseBits(bits,chanBW,numES,numCBPS,numBPSCS);

The parsed sequence is a three-dimensional array of bits.

size(parsedBits)

ans = 1×3

   936     3     2

parsedBits(1:5,:,:)

ans = 5×3×2 int8 array
ans(:,:,1) =

   1   0   1
   0   1   1
   1   0   1
   0   0   0
   1   0   1


ans(:,:,2) =

   1   1   1
   1   1   1
   0   0   1
   1   1   0
   1   0   0

Get Bit Order of OFDM Symbol

Get the bit order after the segment parsing of an OFDM symbol of an S1G configuration with a channel bandwidth of 16 MHz, and two spatial streams.

Define the input parameters. Set the channel bandwidth to 16 MHz, the number of coded bits per OFDM symbol to 1872, the number of spatial streams to 2, the number of encoded streams to 1, the number of coded bits per subcarrier per spatial stream to 2 and the number of OFDM symbols to 2. Calculate the number of coded bits per OFDM symbol per spatial stream by dividing the number of coded bits per OFDM symbol by the number of spatial streams.

chanBW = 'CBW16';
numCBPS = 1872;
numSS = 2;
numES = 1;
numBPSCS = 2;
numSym = 1;
numCBPSS = numCBPS/numSS;

Create the input sequence.

sequence = (1:numCBPS*numSym).';
inp = reshape(sequence,numCBPSS*numSym,numSS);

Perform segment parsing on the sequence.

parsedSequence = wlanSegmentParseBits(inp,chanBW,numES,numCBPS,numBPSCS);

The parsed sequence is a three-dimensional array containing the corresponding bit order.

size(parsedSequence)

ans = 1×3

   468     2     2

Input Arguments

bits — Input sequence

matrix

Input sequence of stream-parsed bits, specified as an (N_CBPSS×N_SYM)-by-N_SS matrix, where:

• N_CBPSS is the number of coded bits per OFDM symbol per spatial stream.

• N_SYM is the number of OFDM symbols.

• N_SS is the number of spatial streams.

Data Types: double | int8

cbw — Channel bandwidth

'CBW1' | 'CBW2' | 'CBW4' | 'CBW8' | 'CBW16 | 'CBW20' | 'CBW40' | 'CBW80' | 'CBW160'

Channel bandwidth in MHz, specified as 'CBW1','CBW2', 'CBW4','CBW8', 'CBW16', 'CBW20', 'CBW40', 'CBW80', or 'CBW160'.

Example: 'CBW160'

Data Types: char | string

numES — Number of encoded streams

1 to 9 | 12

Number of encoded streams, specified as an integer from 1 to 9, or 12.

Data Types: double

numCBPS — Number of coded bits per OFDM symbol

positive integer

Number of coded bits per OFDM symbol, specified as a positive integer. When cbw is 'CBW16' or 'CBW160', numCBPS must be an integer equal to 468×N_BPSCS×N_SS, where:

• N_BPSCS is the number of coded bits per subcarrier per spatial stream.

• N_SS is the number of spatial streams. It accounts for the number of columns (second dimension) of the input bits.

Data Types: double

numBPSCS — Number of coded bits per subcarrier per spatial stream

1 | 2 | 4 | 6 | 8

Number of coded bits per subcarrier per spatial stream, specified as log2(M), where M is the modulation order. Therefore, numBPSCS must equal:

• 1 for a BPSK modulation

• 2 for a QPSK modulation

• 4 for a 16QAM modulation

• 6 for a 64QAM modulation

• 8 for a 256QAM modulation

Data Types: double

Output Arguments

y — Segment-parsed bits

matrix | 3-D array

Segment-parsed bits, specified as an (N_CBPSSI×N_SYM)-by-N_SS-by-N_SEG array, where:

• N_CBPSSI is the number of coded bits per OFDM symbol per spatial stream per interleaver block.

• N_SYM is the number of OFDM symbols.

• N_SS is the number of spatial streams.

• N_SEG is the number of segments. When cbw is 'CBW16' or 'CBW160', N_SEG is 2. Otherwise it is 1.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2017b