Frequency shift keying

As technology becomes increasingly able to meet the requirements, interest in faster, noncoherent, frequency hopping rates to reduce the jamming of communication has heightened. The focus of this paper is on the performance of the fast frequency hopping spread spectrum system operating in the presence of partial band noise jamming. In this paper we consider a communication system that transmits binary data sequence or M frequency shift keying over a channel. With non- coherent detection, the MFSK tones on a given hop must be separated in frequency by an integer multiple of chip rate to provide orthogonality. The worst case partial-band noise jammer chooses fraction ( ρ ) to maximize the bit error probability (Pb) for a given M and signal to noise ratio. It has been observed from the simulation results that increases with K, illustrating the effectiveness of worst-case jamming ( wc ρ ) against FH/MFSK signals at typical operating points. It may be noted that wc ρ

In this paper, a transistor-level simulation result of a Zero crossing BFSK demodulator is presented. The detector will be integrated into a frequency-hopped spread spectrum receiver operating in the 863-870 MHz ISM band, using the zigbee protocol (IEEE 802.15.4). This end to demodulate a received bit sequence with a bit rate equal to 20 kbps using 0.35 μm CMOS technology and a 3 V power supply. The proposed demodulator dedicated to an application of low power and low cost can maintain good performance under process variation. The BER results show that the proposed demodulator needs only 10.9 dB input signal_to_noise ratio to achieve a BER of 10-3 as specified in zigbee standard.

Multi-hop communication systems gained popularity in wireless communications; they can be used to extend the coverage of the network and reduce the transmitted power. The transmission of data from the source node to the destination node in multi-hop communications undergoes through intermediate relay nodes. In this paper, we study the performance of multi-hop communication systems, in terms of average bit error rate (BER) with Binary frequency shift keying assuming the κ-µ fading channel model. Due to the difficulty in finding the probability density function (PDF) of the end-to-end signal to noise ratio (SNR) and hence for the performance metrics, we use Gaussian Mixture (GM) approximation technique to approximate the PDF of the end to end SNR assuming the κ-µ fading models as weighted sums of Gaussian distributions. Numerical results are provided for the BER of binary frequency shift keying (BFSK) of amplify and forward (AF) multi-hop communication systems assuming different values for the fading parameters (and for different number of hops. Numerical results are validated by comparing them with simulation results.