## 1 Introduction  
Recently, there has been a rapid increase in the demand for high data rates in modern wireless communications [1]. Nevertheless, an inevitable fading phenomenon severely affects the bit error rate (BER) performance of wireless communication systems [2]. A multiple-input multiple-output (MIMO) technique has been adopted as a useful solution to combat the effect of the fading channel, since it has the potential to increase the data rate and to improve the BER performance of the wireless link [3]. However, small handheld wireless devices may not be capable of supporting multiple antennas due to size, cost, or hardware limitations [4]. The cooperative communication suggested in [5, 6] enables one to address these drawbacks by creating a virtual MIMO. Cooperative techniques can also be merged with channel codes to achieve coded cooperative diversity. Different channel coding schemes such as convolution codes [7], turbo codes [8], low density parity check (LDPC) codes [9], and polar codes [10] have been utilized in coded cooperative communication. Furthermore, cooperative techniques can be used in cellular communications [11, 12, 13]. Spatial modulation (SM) [14] is a recently developed MIMO technique that boosts spectral efficiency by utilizing antenna indices to convey information. In SM, only one transmit antenna is active at each time slot. Therefore, drawbacks, such as inter-channel interference (ICI) and inter-antenna synchronization (IAS), are alleviated. Furthermore, as compared to existing vertical bell labs layered space-time (VBLAST) architecture [14; 15; 16; 17], SM significantly increases BER performance and decreases the transceiver complexity [14]. In [18], an optimal hard maximum likelihood detection (MLD) for SM was discussed. Furthermore, the soft output MLD for SM was proposed in [19]. There are many achievements related to SM when combined with channel codes. In [20], an LDPC-coded SM scheme was proposed and investigated. In [21], it was proven that the integration of polar codes and SM can offer a superior performance. Later, the authors in [22] discussed and studied a polar-coded SM with multiple antennas at a transceiver in which the multi-level construction of polar codes was employed. Turbo codes were firstly introduced in 1993 [23]. Since then, they have attracted much attention from many scholars. The performance of a turbo code is based on its distance spectrum. A good interleaver plays an important role in shaping the weight distribution that eventually controls the performance of communication systems [24]. Hence, the interleaver is regarded as a vital part in the design of turbo codes. To date, many researchers have designed different types of interleavers [25; 26; 27; 28; 29] for the turbo code. In [28], it was well proven that the code matched interleaver (CMI) is the optimum interleaver of turbo codes. In [30], the authors analyzed and discussed the BER performance of asymmetric turbo codes with the CMI. To the best of our knowledge, asymmetric turbo coded SM (ATC-SM) as an integration of asymmetric turbo codes based on the CMI and SM with higher-order modulation in non-cooperative scenarios, has not been investigated. Therefore, the exploration of ATC-SM is still an open research problem. In order to make full use of the benefits of coded cooperation techniques, we further extend ATC-SM to a coded cooperative scenario, i.e., asymmetric turbo-coded cooperative SM (ATCC-SM). In the ATCC-SM scheme, two sources work in full duplex mode. The contributions of this manuscript can precisely be written as:  
* An asymmetric turbo-coded SM (ATC-SM) technique is proposed. The proposed scheme adopts a higher order modulation such as 16 QAM, 32 QAM and 64 QAM. * The proposed scheme is further extended to coded-cooperative scenarios with two sources, such as the asymmetric turbo-coded cooperative SM (ATCC-SM) technique. * The asymmetric turbo-coded vertical bell labs layered space-time (ATC-VBLAST) is also devised as an appropriate benchmark for the proposed ATC-SM scheme.