A Novel Uplink Multiple Access Technique Based on Index-Modulation Concept

Joint User Pairing, Channel Assignment and Power Allocation in NOMA based CR Systems

“…The constraint in Equation (4) guarantees that the power allocation at the ST follows the power budget where P T is the available power at the ST. The minimum rate requirement (R T ) of each user is ensured by Equations (5) and (6). The constraint in Equation (7) guarantees that each weak user pairs with one and only one strong user and is allocated one channel.…”

“…Recently, non-orthogonal multiple access (NOMA) [3] has come forward and been shown to outperform OMA [4]. Some common techniques of NOMA include index modulation [5,6], code division [7], and power domain [8]. The power domain NOMA is considered to be the backbone of the 5G communication networks because of least computational complexity and excellent performance.…”

Low-Complexity Detection for Index Modulation Multiple Access

“…I NDEX modulation (IM) is an efficient transmission technique, which carries the additional information bits through indices of active medias [1]- [8], where the medias can be orthogonal frequency division multiplexing (OFDM) subcarriers in the frequency domain [9], transmit or receive antennas in the spatial domain [10], spreading codes in the code domain [11], time slots or pulses in the time domain [12], [13], etc. Because only partial resource is used to convey signals and the remaining resource keeps idle, IM results in high energy efficiency (EE) and reduced inter-channel interference (ICI).…”

“…Due to the high EE and anti-interference property, IM technique has been widely used in cognitive radio (CR) networks [14], cooperative networks [15], [16], and multiple access (MA) schemes [12], [17], [19]. In [14], the inactive subcarriers of orthogonal frequency division multiplexing with index modulation (OFDM-IM) are utilized to transmit the secondary user's signals in CR networks.…”

“…In order to improve the system performance, multiple relays are employed for OFDM-IM relay systems in [16]. Recently, the index modulation multiple access (IM-MA) scheme is proposed to facilitate the uplink multi-user MA system in [12], which leads to better performance than that of the conventional orthogonal MA scheme. Note that the carrier in IM-MA can also be time slot, frequency band, spread code, etc., as indicated in [17].…”