Modulator Category Block Listing

The following blocks are included in the Modulator category :

• Amplitude Modulation (AM)
• Differential PSK Modulator
• Frequency Modulation (FM)
• Frequency Shift Keying (FSK) Modulator
• Gaussian FSK (GFSK) Modulator
• Gaussian MSK (GMSK) Modulator
• I/Q Modulator
• Minimum Shift Keing (MSK) Modulator
• Phase Modulation (PM)
• Pulse Position Modulation (PPM)
• Phase Shift Keing (PSK) Modulator
• Quadrature Amplitude Modulation (QAM)
• Pulse Amplitude Modulation (PAM)
• Staggered QPSK (SQPSK) Modulator

Amplitude Modulation (AM)

This block performs double-sideband amplitude modulation (DSB-AM) of the input signal based on the selected modulation parameters. Two versions of this block are provided: one producing a complex output and the other producing a real output.

The AM block belongs to the family of analog modulators. In AM, the information is transmitted by varying the carrier signal amplitude according to the input signal level. The carrier frequency remains constant. This block accepts an analog signal as its input.

Differential PSK Modulation

This block implements differential phase shift keying (DPSK) modulation. There are two versions of this block: one producing a complex output and the other producing a real output.

The Differential PSK block belongs to the family of digital modulators. In DPSK modulation the digital information is transmitted by increasing or decreasing the carrier phase depending on the input data values. The carrier amplitude remains constant.

The Differential PSK block accepts a symbol number as its input and maps it to a phase transition value as specified via an external mapping file. Supported DPSK modes include DBPSK, DQPSK, pi/4DQPSK, D8PSK, D16PSK and D32PSK.

Frequency Modulation (FM)

This block performs frequency modulation (FM) of the input signal based on the selected block settings. Two versions of this block are provided: one producing a complex output and the other producing a real output.

The FM block belongs to the family of analog modulators. In FM, the information is transmitted by varying the carrier frequency according to the input signal level. The carrier amplitude remains constant.
The FM block takes an analog signal as its input.

Frequency Shift Keying (FSK) Modulator

This block performs frequency shift keying (FSK) modulation of the input signal based on the selected modulation parameters. Two versions of this block are provided: one producing a complex output and the other producing a real output.

The FSK block belongs to the family of digital modulators. In FSK modulation, the information is transmitted by varying the carrier frequency between N frequency settings depending on the input signal level. The carrier amplitude remains constant. The FSK block accepts a symbol number as its input in the range of [0, N-1].

Gaussian FSK (GFSK) Modulator

This block implements a Gaussian Frequency Shift Keying (GFSK) modulator as a compound block. In GFSK modulation, the digital information is transmitted by shifting the carrier frequency between two states.

This block employs a Gaussian FIR Filter and an FM Modulator as its internal components. The internal parameters of each of these blocks may need to be specified for proper operation, in addition to setting the BT product, symbol rate, and FM deviation global parameters. The default settings reflect a Bluetooth implementation.

Gaussian MSK (GMSK) Modulator

This block implements a Gaussian Minimum Shift Keying (GMSK) modulator as a compound block. In GMSK modulation, the digital information is transmitted by shifting the carrier frequency between two states with a frequency offset of ± 0.25 of the symbol rate. This represents a special case of GFSK.

This block employs a Gaussian FIR Filter and an FM Modulator as its internal components. The internal parameters of each of these blocks may need to be specified for proper operation, in addition to setting the BT product and the symbol rate global parameters.

I/Q Modulator

This block performs generic Amplitude Phase Modulation given a pair of analog In-phase (I) and Quadrature (Q) signal inputs. Two versions of this block are provided: one producing a Complex output and the other producing a Real output.

The block can be used to produce either digital or analog modulation. The information is transmitted by varying both the carrier amplitude and phase according to the I & Q input signals. Block parameters include the carrier frequency, initial phase, and amplitude scaling factor. This block takes two parallel analog signals as its inputs.

Minimum Shift Keying (MSK) Modulator

This block performs minimum shift keying (MSK) modulation of the input signals based on the selected modulation parameters. Two versions of this block are provided: one producing a complex output and the other producing a real output.

The MSK block belongs to the family of digital modulators. MSK modulation is similar to SQPSK modulation, except that sinusoidal pulse shaping is applied to the data signal prior to modulation.
MSK modulation can also be viewed as a form of FSK modulation with tones at Fc ± R/2, where R is the symbol rate.

MSK modulation results in lower sidelobe energy levels than both QPSK and SQPSK modulation. The MSK block accepts two binary signals as its input: I and Q data, respectively.

Phase Modulation (PM)

This block performs phase modulation (PM) of the input signal based on the selected modulation parameters. Two versions of this block are provided: one producing a complex output and the other producing a real output.

The PM block belongs to the family of analog modulators. In PM, the information is transmitted by varying the carrier phase according to the input signal level. The carrier amplitude remains constant.
The PM block accepts an analog signal as its input.

Pulse Position Modulation (PPM)

This block performs PPM of the input signal based on the selected modulation parameters. In PPM, the information is transmitted by varying the occurrence of a rectangular pulse within a pre-defined symbol frame. The location of the pulse is proportional to the input signal level. Pulse spacing is automatically calculated, and no portion of the pulse ever occurs beyond the symbol frame boundaries.

The PPM block belongs to the family of digital modulators. The PPM block accepts a symbol number as its input, and outputs a baseband real signal. The input is rounded to the closest allowed symbol number.

Phase Shift Keying (PSK) Modulator

This block performs phase shift keying (PSK) modulation of the input signal based on the selected modulation parameters. In PSK modulation, the digital information is transmitted by varying the carrier phase between known phase states. The carrier amplitude remains constant. Two versions of this block are provided: one producing a complex output and the other producing a real output.

This block belongs to the family of digital modulators. It accepts as its input a binary signal (BPSK only) or a symbol number and maps it to the constellation point specified in an external PSK map file. The following constellations are available: BPSK, QPSK, 8-PSK, 16-PSK, and 32-PSK.

Quadrature Amplitude Modulation (QAM)
Pulse Amplitude Modulation (PAM)

This block performs quadrature amplitude modulation (QAM) or pulse amplitude modulation (PAM), depending on the selected modulation parameters. Two versions of this block are provided: one producing a complex output and the other producing a real output.

The QAM/PAM block belongs to the family of digital modulators. This block accepts a symbol number as its input and maps it to the constellation point specified in an external QAM/PAM map file. The following constellations are available: 16-QAM, 32-QAM, 64-QAM, 256-QAM, 4-PAM, and 8-PAM.

Staggered QPSK (SQPSK) Modulator

This block performs staggered quadrature phase shift keying (SQPSK) modulation of the input signal based on the selected modulation parameters. Two versions of this block are provided: one producing a complex output and the other producing a real output.

The SQPSK block belongs to the family of digital modulators, and is also known as offset QPSK (OQPSK). In SQPSK modulation, the digital information is transmitted by varying the carrier phase among four states equally spaced at pi/2 rad increments. The carrier amplitude remains constant.

The data on the Q channel input is delayed ½ symbol duration relative to the I channel data. This ensures that at any given time, only one of the two data channels (I or Q) may undergo a transition. As a result, the modulated signal phase never changes by more than pi/2 rad, and the modulated spectrum exhibits lower sidelobes than ordinary QPSK.

The SQPSK block accepts two binary data streams as its input (I and Q data, respectively) and uses Gray encoding in its mapping. A real-to-integer conversion (rounding) is performed on the inputs. To demodulate SQPSK, a regular QPSK detector may be used.