BPSK-Binary Phase Shift Keying

This page describes Binary Phase Shift Keying technique or BPSK modulation basics.It mentions link to difference between BPSK and QPSK.BPSK matlab code link is also provided.

As mentioned BPSK stands for Binary Phase Shift Keying. It is digital modulation technique.

As mentioned in the constellation diagram binary 1 and binary 0 are represented by different carrier phases each is 180 degree apart. The simplest BPSK scheme uses two phases to represent the two binary digits and is known as binary phase-shift keying. The resulting transmitted single for one bit time is

S (t) =A* cos (2*pi*fc*t) for binary 1

S (t) =A *cos (2*pi*fc*t+pi) for binary 0

This is regarded as the most robust digital modulation technique and is used for long distance wireless communication. When CINR is poor base station choose BPSK modulation technique in most of the adaptive modulation technique adopted in cellular communication.

It is less immune to the interference. Typically KMOD is 1 for BPSK in the equation.


Figure mention the constellation points and encoding rule, which is taken from IEEE standard 802.16-2004 to demonstrate BPSK concept.

BPSK Applications

The BPSK modulation is a very basic technique used in various wireless standards such as CDMA, WiMAX (16d, 16e), WLAN 11a, 11b, 11g, 11n, Satellite, DVB, Cable modem etc. It is considered to be more robust among all the modulation types due to difference of 180 degree between two constellation points. Hence it can withstand severe amount of channel conditions or channel fading. It is used in OFDM and OFDMA to modulate the pilot subcarriers used for channel estimation and equalization. As we know different channels are used for specific data transmission in cellular systems. The channels used to transmit system related informations which are very essential are modulated using BPSK modulation.

What is difference between BPSK and QPSK types

Refer BPSK vs QPSK page which decribes difference Between BPSK and QPSK modulation types.
Refer QPSK vs OQPSK vs pi/4QPSKwhich describes difference between QPSK,OQPSK and pi/4QPSK modulation types.


Refer following link which mentions BPSK MATLAB code and provide matlab codes for other modulation types.
BPSK QPSK 16QAM 64QAM modulation matlab code

Modulation types related links

what is modulation   MSK and GMSK modulation   8-PSK modulation   QPSK modulation   QAM modulation   C4FM vs CQPSK   Differential Encoder and Decoder  

RF and Wireless Terminologies