# Transmitter Diversity Gain Technique Aided Irregular Channel Coding for Mobile Video Transmission
###### Abstract
Consequently, the SC technique picks up the signal with the highest SNR having a diversity gain smaller as compared to the MRC technique, but with lower complexity, as it requires only one radio frequency chain. Both STC and STBC techniques use coherent detection, which required Channel State Information (CSI) or path gains matrix in the case of a spatial diversity in the fading channel [2]. Furthermore, CSI can be predicted by transmitting training symbols before transmitting the information, but, when the training sequences becomes outdated in fast fading, it directly increases the overhead and the power consumption. In [8], the authors proposed a space-time signal construction method by combining orthogonal designs with sphere packings for the correlated Rayleigh fading channel that is inspired by space-time codes. The performance improvement of STBC scheme can be further improve by iteratively channel decoding along with the concatenation of sphere packing (SP) aided modulation [9]. Differential detection techniques are used to overcome the problem of finding the CSI. Therefore, multidimensional SP modulation assisted Differential Space Time Spreading assisted (SP-DSTS) provides better performance in terms of error probability and to overcome the channel dependency for decoding the received modulated symbols [10; 11]. The proposed scheme uses the differential space time spreading (DSTS) technique, which encodes the symbol both in space domain by using two Tx antennas and in time domain by transmitting a symbol in two time periods of transmission for attaining diversity and coding gain. Moreover, DSTS is a suitable technique when the training symbols become outdated for each instance of a transmission. Differential is a complex scheme, but is reduces the computational complexity in fading channels. Three different novel error protection schemes and two arrangements of partitioning order [A-B-C] and [B-A-C] are proposed. In partitioning order [A-B-C], the partitions types are prioritized as A, B, & C. Partition A is protected more than partition B, which is consequently protected more than partition C while using IRCC subcodes. Similarly, in partitioning order [B-A-C], the partitions are prioritized as B, A, and C, where partition B is protected more than partition A, which is protected more than partition C using the subcodes of multi-code IRCC. In multi-code IRCC, various constituent error protection subcodes are encoding the information bits according to their relative importance. The redundancy is iteratively utilized in the decoder side for the enhancement of high Bit Error Rate (BER) performance. A transmitter diversity gain technique is incorporated in order to further improve the performance of the proposed work, such that the coded video bitstream is passed to DSTS and SP modulation, which overcome channel estimation dependency. The motivation of this research work is to investigate the mechanism of performance improvement using iterative coding, while employing convergence capable inner and outer code, transmitter diversity gain using space-time signal construction, differential detection, and its impact on the performance of a highly compression efficient coded video stream. The motivations and contributions of the proposed work are summarized, as given below:  
* Three different error protection schemes and two arrangements of H.264 partitions have been established. * The proposed work uses irregular convolutional codes for seeking code-rates on which turbo cliff is obtained for achieving the prioritized partition. * Space-time constellation has been included to observe the performance of the system on time-varying correlated Rayleigh fading channel. * Space-time spreading is included, because it does not require the knowledge of the channel coefficients at the base. * Space-time spreading codes only requires one spreading code per user. * Space-time spreading method primarily targets systems that use two-transmitter and one-receiver antenna.