- 1 and 0
- 0 and 1
- 11 and 00
- 00 and 11
Explanation: Binary Frequency Shift Keying (BFSK) is a type of frequency modulation technique used in digital communication systems. In BFSK, two distinct frequencies are used to represent the binary values 0 and 1. The term “mark” refers to the higher frequency, which represents the binary value 1, and the term “space” refers to the lower frequency, which represents the binary value 0.
Example: Let’s consider a BFSK system where the carrier frequencies are 1000 Hz and 1200 Hz. In this case, when a binary 1 (mark) is transmitted, the carrier frequency is 1200 Hz, and when a binary 0 (space) is transmitted, the carrier frequency is 1000 Hz. The receiver can distinguish between the two frequencies and recover the binary data.
- BFSK is a coherent modulation technique, which means that the receiver uses a reference signal (e.g., a local oscillator) to demodulate the incoming signal and recover the transmitted data.
- BFSK has a relatively low data rate compared to other modulation techniques, such as Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM), but it is more resistant to noise and interference.
- BFSK is used in various applications, including low-data-rate communication systems, wireless sensor networks, and frequency-hopping spread spectrum (FHSS) systems.
Relevant Stats: The bit error rate (BER) for BFSK in an additive white Gaussian noise (AWGN) channel can be estimated using the following formula:
BER = 0.5 * exp(-Eb/N0)
where Eb is the energy per bit, and N0 is the noise power spectral density. This formula indicates that the BER performance of BFSK depends on the ratio of Eb/N0, which is also known as the signal-to-noise ratio (SNR). As the SNR increases, the BER decreases, meaning that the probability of bit errors reduces, resulting in improved communication reliability.
In summary, Binary Frequency Shift Keying (BFSK) is a digital modulation technique where the mark and space respectively represent binary values 1 and 0. This technique uses two distinct frequencies to encode the binary data, making it more resistant to noise and interference than other modulation schemes. However, BFSK has a lower data rate compared to more advanced modulation techniques.