Distributed Regenerative DF SISO Wireless Mobile Networks under PCSI and ICSI Yazan Ibdah, Kanghee Lee, and Wenhao Xiong Department of Electrical Engineering and Computer Science, Wichita State University, Wichita, Kansas 67260, U.S.A. Emails: {yxibdah, kxlee1, wxxiong}@wichita.edu Abstract—This paper studies the regenerative decode-and- forward (DF) for mobile wireless relay networks under per- fect channel state information (PCSI) and imperfect channel state information (ICSI). The wireless mobile network under study consists of one-source-one-destination mobile pair and  - multibranch mobile relay nodes. The proposed detection tactics, employing the maximum ratio combiner (MRC) principle, are proposed for a mobile network experiencing either PCSI or PCSI. These tactics are applied at mobile relays and the mobile destination accordingly to optimally detect received signals. Using the proposed detection schemes, Monte-Carlo simulations are performed to evaluate the system performance for the distributed regenerative DF single-input single-output (SISO) mobile wireless relay network. Performance comparisons for cases, such as ICSI only in source-relay links and ICSI only in relay-destination links, were also included. Index Terms—Wireless mobile network, decode-and-forward, perfect and imperfect channel state information, maximum ratio combiner, cascaded Rayleigh, mobile-to-mobile. I. I NTRODUCTION In wireless mobile communication network, distributed mobile relays can assist message delivery from a mobile source to a mobile destination. Relaying schemes are catego- rized into three groups: 1) the nonregenerative amplify-and- forward; 2) the regenerative decode-and-forward (DF); and 3) compress-and-forward (CF) [1]–[13]. Relay nodes employing the regenerative DF scheme completely decode their received signals and reencode them, then retransmit them toward the destination. Different systems such as single-input-single-put (SISO), single-input-multiple-output (SIMO), and multiple-input-mult- iple-output (MIMO) wireless fixed communication systems for three relay schemes were studied in [1]–[15]. In addition, imperfect channel state information (ICSI) was investigated for fixed nodes in wireless relay networks. SISO, SIMO, and MIMO systems were studied in [5]–[11]. In particular, the multihop and multibranch fixed relay schemes for AF and DF wireless network under perfect channel state information (PCSI) and ICSI were studied in [14], [15], respectively. Namely, distributed regenerative DF SISO wireless relay net- work under PCSI and ICSI was studied in fixed-to-fixed scenarios. In other words, mobility effect was not investigated. By employing the DF tactic in this current paper, the source Fig. 1. A regenerative DF SISO wireless mobile network for one-source- one-destination mobile node pair and  mobile relay nodes under PCSI. node broadcasts its symbol in the first time slot, while relays listen to medium. Upon receiving the signal from the source node, each relay nodes decodes the signal using the maximum ratio combiner (MRC). Transmission time is divided among relay nodes. In other words, each relay is assigned a time slot at which it can transmit its message; sets idle until its new turn comes in a new cycle. Finally, by implementing the scaling factor MRC (S-MRC) based on detection scheme at the destination node, the destination optimally detect the originally transmitted message. Two main approaches are available in the literature to simulate a statistical mobile-to-mobile fading channel. In [16], authors proposed a channel based on two rings of uniformly distributed scatters, one ring around the source and the other ring around the destination. The cascaded Rayleigh channel model employed in this paper represents the second approach. This cascaded Rayleigh approach is based on two in- dependent sets of scatters: 1) one around the source; and 2) the second around the destination. The concept for this approach was initially suggested in [17], while the model that meets the desired statistical properties was officially presented in [18]. Outdoor measurements were reported in [19], [20], and recommended a cascaded Rayleigh channel to model mobile- to-mobile scenarios. In summary, this current paper studies the regenerative DF wireless mobile relay scheme under PCSI and ICSI in a multibranch mobile scenario without the source-destination direct link. Similar to work done for AF in [6]–[10], this