# How many different symbols are possible at the output of a 16-QAM modulator?

## 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.

### How many amplitudes and phases are there in 16-QAM?

… components. There are 16 symbols in the QAM design and each symbol has two gray coded bits of I and Q . A Constellation diagram is used to plot those symbols in rectangular space. The 16-QAM design has 4 amplitudes and 12 phases.

How many bits per symbol are used in 16-QAM?

four bits
16 QAM has four bits per symbol for each polarization, so to encode our 12 bits, we could break them up into three groups of four, thereby only using 3 symbols in one polarization.

How many bits each signal of 64 QAM can carry?

With 64-QAM, two of the six bits of each I/Q value pair are used for the high-priority path and the remaining four bits for the low- priority path. With 16-QAM, two out of four bits are allocated to each path.

## What is the meaning of 16 QAM?

16 Quadrature Amplitude Modulation. This is a modulation technique in which the carrier can exist in one of sixteen different states. As such, each state can represent four bits – 0000 through to 1111, per symbol change.

### What is the meaning of 16-QAM?

What is the difference between 8 QAM and 16 QAM?

Even 256 QAM provides more bandwidth than 64 QAM. A 64 QAM provides 38 Mbps bandwidth for stream while 256 QAM provides more than that. QAM is higher order form of modulation so it can carry more information….Comparison Of 4 QAM 8 QAM 16 QAM 32 QAM Etc.

MODULATION BITS PER SYMBOL SYMBOL RATE
64QAM 6 1/6 bit rate

How do I generate 16-QAM in Matlab?

Define parameters.

1. 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)
2. rng default; dataIn = randi([0 1],n,1); % Generate vector of binary data.

## What is the trade off of using 16-QAM over BPSK?

16 QAM provides 4:1 efficiency of transmission over BPSK.

### What is the advantage of QPSK over 16-QAM?

The spectral width of QPSK is wider than that of QAM. QPSK conveys 2-bit simultaneously while in case of QAM the number of bits depends on the type of QAM such as 16 QAM, 32 QAM, 64 QAM, 128 QAM, 256 QAM conveys 4, 5, 6, 7, 8 bits respectively. The performance of QPSK is superior to QAM.

What is 8QAM?

Digital QAM (8QAM) In 8QAM, three input bits generate eight modulation states using four phase angles on 90 degree boundaries and two amplitudes (4 phases X 2 amplitudes = 8 states). Digital modulation greater than 8QAM is difficult to visualize.

Benefits or advantages of QAM ➨The major benefit of QAM modulation variants is efficient usage of bandwidth. This is due to the fact that QAM represent more number of bits per carrier. For example, 16QAM maps 4 bits per carrier, 64QAM maps 6 bits per carrier, 256QAM maps 8 bits per carrier and so on.

## What are interior and edge points in 16 QAM?

In 16 -QAM, four constellation points ( ± d 2, ± d 2) are “interior” points while the remaining 12 are “edge” points or “corner” points for which at least one of the coordinates is ± 3 d 2. Thus, in n measurements ( X i, Y i) of successive transmitted symbols, some of the X i will equal ± d 2 + N I i while others will be ± 3 d 2 + N I i.

### Why are the constellation points of 64-QAM normalized?

Hence the constellation points of 64-QAM are normalized with the factor to ensure that the average energy over all symbols is one. Extending this to a general M-QAM constellation mapping, where is a power of 2. The elements of the alphabet are , where .

What are the different variants of 16-QAM?

There are many variants to this technique. Most popular are 16-QAM, 64-QAM and 256-QAM . The example below explains 16-QAM. The 16 qam bits per symbol are 4 (four). This means in 16-QAM each symbol represents 4 bits as mentioned in the 16-QAM constellation diagram above. For example if the input is 1010 then the output is (-3-j*3)*KMOD.

What is the peak power of 16 QAM modulator and demodulator?

In both 16 QAM Modulator and Demodulator blocks, set the Constellation ordering to Gray, set the Normalization method to Peak Power, and set the value of the Peak power to 1 Watt.