Outage and ergodic sum‐rate performance of cooperative MIMO‐NOMA with imperfect CSI and SIC

Abstract

Summary In this paper, we examine a half‐duplex cooperative multiple‐input multiple‐output non‐orthogonal multiple access system with imperfect channel state information (CSI) and successive interference cancelation. The base station (BS) and mobile users with multi‐antenna communicate by the assistance of a CSI based or fixed gain amplify‐and‐forward (AF) relay with a single antenna. The diversity schemes, transmit antenna selection, and maximal ratio combining are applied at the BS and mobile users, respectively. We study the system performance in terms of outage probability (OP) and ergodic sum‐rate. Accordingly, the exact OP expressions are first derived jointly for the CSI based and fixed gain AF relay cases in Nakagami‐m fading channels. Next, the corresponding lower and upper bound expressions of the OP are obtained. The high signal‐to‐noise ratio analyses are also carried out to demonstrate the error floor value resulted in the practical case and achievable diversity order and array gain in the ideal case. Moreover, the lower and upper bounds of the ergodic sum‐rate expressions are derived together for the CSI based and fixed gain AF relay cases. Finally, the Monte‐Carlo simulations are used to verify the correctness of the analytical results.

Performance analysis for user selection‐based downlink non‐orthogonal multiple access system over generalized fading channels

“…Since SIC is not employed at the f th UE, its received SINR will be the same as in (1). However, with imperfect SIC, the received SINR at the n th UE can be modified as 31‐33 where , , is the level of residual interference due to imperfect SIC at the n th UE. By using the value of in (35) and following the steps in Section 3.2, the sum‐rate and achievable rates can be evaluated numerically for the imperfect SIC case.…”

Performance analyses of TAS/Alamouti‐MRC NOMA system with channel estimation error, feedback delay, and imperfect SIC

“…It is quite obvious that the aforementioned studies do not consider channel estimation error (CEE), feedback delay (FBD), and imperfect SIC (ipSIC) which are crucial not to be ignored although they comprise of multiple antenna and relaying techniques. Nevertheless, there are some investigations on MIMO-NOMA with/without relaying techniques considering practical impairments (such as CEE, FBD, and ipSIC) [34][35][36][37][38][39] to demonstrate the effects on the system performance, but still remain limited. In particular, in Reference 34, the system considered in Reference 25 is generalized to all STBC schemes, and OP and ergodic capacity (EC) performances are investigated by taking into account CEE, FBD and imperfect SIC.…”

“…In Reference 36, OP performance of NOMA based dual‐hop network, where transmit antenna selection (TAS) and MRC techniques are applied at the BS and users respectively, is analyzed for channel state information (CSI) based relay by considering the effect of CEE over Nakagami‐ m fading channels. In Reference 37, the system in Reference 36 is jointly analyzed for both CSI based and fixed gain relay in the presence of CEE and ipSIC. In Reference 38, hybrid MRT/RAS scheme is investigated in both hops of a cooperative MIMO‐NOMA system over Nakagami‐ m fading channels under the consideration of CEE.…”

Joint Transmit-and-Receive Antenna Selection System for MIMO-NOMA With Energy Harvesting

“…Also, the transmit antenna selection (TAS) and maximal ratio combining (MRC) schemes are applied at the BS and users, respectively. Then, the work [3] is extended to [4]- [9] for the fixed-gain AF relay with perfect CSI (pCSI) [4], for the CSI based gain AF relay with imperfect CSI (ipCSI) [5], and for both CSI based and fixed-gain AF relay in the ipCSI and imperfect successive interference cancellation (ipSIC) cases [6]. The OP and ergodic sum-rate are studied in [7] under Rayleigh fading channels for the dual-hop NOMA network, where joint transmit receive antenna selection (JTRAS) and receive It is worth to mention that [11]- [23] use a relay with single transmit and single receive antenna while [24] uses a relay with single transmit and multiple receive antennas.…”