info

Characteristic information about OQPSK Demodulator

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Syntax

oqpskdemodInfo = info(oqpskdemod)

Description

oqpskdemodInfo = info(oqpskdemod) returns a structure containing information for the comm.OQPSKDemodulator System object™.

example

Examples

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Open Live Script

Perform OQPSK modulation and demodulation and apply root raised cosine filtering to a waveform.

System initialization

Define simulation parameters and create objects for OQPSK modulation and demodulation.

sps = 12; % samples per symbol
bits = randi([0,1],800,1); % transmission data

oqpskMod = comm.OQPSKModulator( ...
    'BitInput',true, ...
    'SamplesPerSymbol',sps, ...
    'PulseShape','Root raised cosine');
oqpskDemod = comm.OQPSKDemodulator(oqpskMod);

Waveform transmission and reception

Use the modulator object to apply OQPSK modulation and transmit filtering to the input data.

oqpskWaveform = oqpskMod(bits);

Pass the waveform through a channel.

snr = 0;
rxWaveform = awgn(oqpskWaveform,snr);

Use the demodulator object to apply receive filtering and OQPSK demodulation to the waveform.

demodData = oqpskDemod(rxWaveform);

Use the info object function to determine the system delay. As shown, you can also compute the system delay based on the filter span in symbols and the configured data option for the modulator or demodulator. 

oqpskdemodInfo = info(oqpskDemod)
oqpskdemodInfo = struct with fields:
    DecimationFactor: 12
               Delay: 20


delay = oqpskdemodInfo.Delay;
delay_mod = (1+oqpskMod.BitInput)*oqpskMod.FilterSpanInSymbols
delay_mod = 
20

delay_demod = (1+oqpskDemod.BitOutput)*oqpskDemod.FilterSpanInSymbols
delay_demod = 
20

Compute the bit error rate to confirm the quality of the data recovery.

[~, ber] = biterr(bits(1:end-delay),demodData(delay+1:end))
ber = 
0

Input Arguments

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OQPSK demodulator, specified as a comm.OQPSKDemodulator System object.

Output Arguments

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OQPSK demodulator information, returned as a structure containing these fields. The OQPSK demodulator object is specified by the input oqpskdemod.

Decimation factor in samples, returned as a positive scalar.

Demodulator delay between input and output signals in samples at the output sampling rate.

Version History

Introduced in R2012a

See Also

Objects