Commutation Code Index DCSK Modulation Technique for High-Data-Rate Communication Systems

Abstract

Abstract-In this work, a novel non-coherent modulation system named Commutation Code Index Differential Chaos Shift Keying (CCI-DCSK) is presented. In the proposed scheme, the benefits of index modulation (IM) are exploited so that the system energy and spectral efficiencies are improved. We are putting forward a CCI-DCSK scheme in which the reference sequence along with its corresponding data bearing orthogonal version are sent within the same time slot to enhance spectral efficiency. Specifically, at the transmitter p additional bits are mapped into the index of the repetition commutation which is performed on the reference signal for the sake of forming its orthogonal version. Furthermore, the modulated bit is spread by the corresponding commutated replica of the reference signal. The reference and orthogonal data bearing signals are then summed within the same time slot prior to transmission. At the receiver, the received signal is first correlated with all possible combinations of the commutated replicas in order to find the index of the correlator output with the maximum magnitude. Subsequently, the maximizing index is then used to estimate the mapped bits, while the output of the corresponding correlator is used to despread the modulated bit via a zero-threshold comparator. To complete the study, analytical expressions for the bit error rate (BER) are derived for both additive white Gaussian noise (AWGN) and multipath Rayleigh fading channels. Finally, performance results of the proposed CCI-DCSK scheme is compared with the state-of-the-art IM-based non-coherent chaotic modulations and is found to be superior and competitive.

Hybrid Modulation Scheme Combining PPM With Differential Chaos Shift Keying Modulation

“…Then the bits mapped by position can be obtained from the decimal-to-binary converting part. For m c mapped bits, the symbol duration of PPM-DCSK, CIM-DCSK and CCI-DCSK is (2 mc +1) * R [2], (2 mc +1) * R and 2 n * R(n ≥ m c ) [7], respectively. Thus they have similar bandwidth efficiency.…”

“…Differential chaos shift keying (DCSK), a modulation scheme proposed for chaotic communications [3], is characterized by its simple transceiver configuration and excellent performance over multipath fading channels [4], only requiring a simple non-coherent demodulator without channel estimators and equalization [5]. Some variants of DCSK, such as permutation index DCSK(PI-DCSK) [6] and code index modulation DCSK (CIM,CCI-DCSK) [1] [7] which used index modulation [8] [9] have also been proposed. A multi-resolution M -ary DCSK with M -ary phase-shiftkeying (MPSK) constellation is proposed based on quadrature chaotic shift keying (QCSK) [10] which offers better BER performance by changing the structure of constellation.…”

A Multiple‐Access Time and Frequency Spectrum‐Spreading Modulation

“…In fact, is considered as the spreading factor and , for ≫ 1, the spectral efficiency. The value of is elaborated in (11).…”

“…Different chaos modulation techniques have been proposed (see, e.g., [8,9] and references therein). In Differential Chaos Shift Keying (DCSK), index modulation is integrated to improve the system's data rate and energy efficiency such as permutation index DCSK (PI-DCSK) [10] and Commutation Code Index DCSK (CCI-DCSK) [11]. Recently, Code Index 2 Wireless Communications and Mobile Computing Modulation (CIM) has been proposed for spread spectrum systems [12].…”

On the performance analysis of a DCSK system under the pulse jamming environment

“…In addition, the emerging index modulation is also integrated into the DCSK system to improve the system’s data rate, energy efficiency, and spectral efficiency, i.e. permutation index-DCSK (PI-DCSK) [10] and commutation code index-DCSK (CCI-DCSK) [11]. Moreover, the DCSK system has also found applications in simultaneous wireless information and power transfer system [12].…”