A Pattern Construction Scheme for Neural Network-Based Cognitive Communication

Abstract

Inefficient utilization of the frequency spectrum due to conventional regulatory limitations and physical performance limiting factors, mainly the Signal to Noise Ratio (SNR), are prominent restrictions in digital wireless communication. Pattern Based Communication System (PBCS) is an adaptive and perceptual communication method based on a Cognitive Radio (CR) approach. It intends an SNR oriented cognition mechanism in the physical layer for improvement of Link Spectral Efficiency (LSE). The key to this system is construction of optimal communication signals, which consist of encoded data in different pattern forms (waveforms) depending on spectral availabilities. The signals distorted in the communication medium are recovered according to the pre-trained pattern glossary by the perceptual receiver. In this study, we have shown that it is possible to improve the bandwidth efficiency when largely uncorrelated signal patterns are chosen in order to form a glossary that represents symbols for different length data groups and the information can be recovered by the Artificial Neural Network (ANN) in the receiver site.

Very-low-SNR cognitive receiver based on wavelet preprocessed signal patterns and neural network

“…In PBCCS, the modulation is performed by using the sinusoidal pattern envelope construction (SPEC) algorithm [10]. The SPEC algorithm is used to prevent unwanted extra spectral usage, and it guarantees that the signal's pattern ends at its initial point to ensure a zero-power density in average and has no high-frequency components.…”

“…• Hidden neurons: due to low complexity and high applicability perspective [10], a single hidden layer with few number of neurons should be used. The number of neurons will be determined by the cross validation method.…”

“…For instance, Xilinx Virtex VI xc6vlx240t-1ff1156 has 768 multipliers (named DSP48E1) [33]. Table 8 shows a comparison between the architecture of the proposed approach compared with the one that is based on time delay ANN (TDNN) [10]. It shows that the total number of multipliers in the FFNN is drastically reduced compared with the TDNN.…”

Reliable, Efficient, and Power Optimized Control-Channel Selection Scheme for Cognitive Radio Networks

“…Such a shift in the spectrum management paradigm requires a robust communication radio that can meet the stringent demands of the future generation of communication systems. Cognitive radio (CR), or reconfigurable radio, seems to be the best technology for dynamic spectrum access [1][2][3][4]. CRs employ the spectrum-sensing scheme to locate empty spots within the radio spectrum band and then utilize the software routines using software-defined radio (SDR) for parameter adjustment.…”

“…The CR can operate in the vacant portion of the licensed band only if they operate under a tolerable interference limit with LUs [5]. From the perspective of the CR, there are five main functions spectrum sensing: spectrum analysis, spectrum decision, spectrum sharing, and spectrum mobility [2][3][4][5]. As an example, the network control systems (NCS) are heavily investigated to manage the packet drop and latency of control-channel [6,7].…”