In-phase and quadrature filter shape index modulation

Abstract This paper proposes a novel modulation scheme called “In Phase and Quadrature-Filter Shape Index Modulation” (IQ-FSIM). It aims to enhance the spectral/energy efficiencies (SE/EE) while generalizing several existing modulations index (IM) domains. In this system, bitstream is divided into three sub-streams. The first mapped using amplitude–phase modulation, other two are separately an of filter shape at in-phase quadrature components. IQ-FSIM in SISO mode enhances SE by $$2\log _2 N$$ 2 log N (double FSIM gain), thanks independent indexation N different shapes on each component changing symbol rate. A low-complexity matched filter-based detector that reaches optimal joint ML performance proposed. theoretical lower bounds for probability error symbol/bit rate (SER/BER) derived validated. computational complexity proposed transceiver estimated compared its predecessor FSIM, where it shown provides up 93.7% reduction along with advantages. addition, results reveal both special case even non-optimal shapes, outperform equivalent schemes with/without IM same AWGN, flat, frequency-selective fading channels.