How do I generate 16-QAM in Matlab?
Define parameters.
- M = 16; % Modulation order (alphabet size or number of points in signal constellation) k = log2(M); % Number of bits per symbol n = 30000; % Number of bits to process sps = 1; % Number of samples per symbol (oversampling factor)
- rng default; dataIn = randi([0 1],n,1); % Generate vector of binary data.
How many different symbols are possible at the output of a 16-QAM modulator?
Each dot in Figure 1.8 is a symbol, as it represents a unique combination of amplitude and phase of the I and Q waves. So, in each symbol period, only one of the ‘dots’ is transmitted. As there are 16 symbols, this version of QAM is called 16-QAM. Figure 1.8 Constellation diagram for 16-QAM.
Is 16-QAM better than QPSK?
The primitive difference between the QAM and QPSK is that the spectral width of QAM is narrower than the QPSK. Furthermore, the BER (Bit Error Rate) of the QAM is higher than the QPSK….Comparison Chart.
| Basis for comparison | QAM | QPSK |
|---|---|---|
| Performance | Average | Better |
| Bit error rate | High | Low |
What is constellation diagram of QAM?
A constellation diagram is a representation of a signal modulated by a digital modulation scheme such as quadrature amplitude modulation or phase-shift keying. It displays the signal as a two-dimensional xy-plane scatter diagram in the complex plane at symbol sampling instants.
How do you create a QAM signal in Matlab?
y = qammod( x , M ) modulates input signal x by using QAM with the specified modulation order M . Output y is the modulated signal. y = qammod( x , M , symOrder ) specifies the symbol order.
What is 16 QAM used for?
In the UK, 16 QAM and 64 QAM are currently used for digital terrestrial television using DVB – Digital Video Broadcasting. In the US, 64 QAM and 256 QAM are the mandated modulation schemes for digital cable as standardised by the SCTE in the standard ANSI/SCTE 07 2000.
How does QAM demodulator work?
QAM demodulator basics The QAM demodulator is very much the reverse of the QAM modulator. The signals enter the system, they are split and each side is applied to a mixer. One half has the in-phase local oscillator applied and the other half has the quadrature oscillator signal applied.
What is the bandwidth of 16 QAM?
In high-capacity digital radio systems, 16 QAM is now in very wide use, e.g. for transmitting a 140 (or 135) Mbits/s data rate in interleaved frequency arrange- ments with 40 MHz spacing between two adjacent cross- polarized carriers. Paper approved by the Editor for Fiber-Optics of the IEEE Communica- tions Society.
How many frequencies does a full duplex QAM 16 modem use?
A full-duplex QAM-16 modem uses two frequencies, one for upstream and the other for downstream.
How do you plot a constellation diagram in Matlab?
Create 32-QAM Constellation Diagram Use the qammod function to generate the 32-QAM symbols with binary symbol ordering. M = 32; data = 0:M-1; sym = qammod(data,M,’bin’); Plot the constellation. Label the order of the constellation symbols.