Three-way Channel Research Articles

Repair of a three-way congenital bronchoesophageal fistula in an adult patient: a case report

BackgroundThe incidence of congenital bronchoesophageal fistulas in adults is rare. Most fistulas discovered in adulthood are often small and can be repaired with a simple one-step method.Case presentationA 46-year-old female patient complained of a 2-month history of chocking, coughing, and a 12 kg drop in weight. The bronchofiberscopy and gastroscopy showed a large fistula, which extended from the esophagus to the main bronchus on both sides, thus forming a special three-way channel which has never been reported. This case was challenging both to the anesthetists and surgeons. The patient was intubated with a sengstaken-blakemore tube, and then received segmental esophageal resection, anastomotic reconstruction, and double-flap repair with esophagus segment in situ.ConclusionWhen the fistula in BEF is large or complicated, appropriate surgical methods should be meticulously designed according to the condition of the patient. The problem of anesthesia intubation should be solved first, to allow a smooth operation. Secondly, a double-layer repair of the airway fistula by using esophageal wall tissues as patch materials is proposed.

Degrees-of-Freedom of the MIMO Three-Way Channel With Node-Intermittency

The characterization of fundamental performance bounds of many-to-many communication systems in which participating nodes are active in an intermittent way is one of the major challenges in communication theory. In order to address this issue, we introduce the multiple-input multiple-output (MIMO) three-way channel (3WC) with an intermittent node and study its degrees-of-freedom (DoF) region and sum-DoF. We devise a non-adaptive encoding scheme based on zero-forcing, interference alignment and erasure coding, and show its DoF region (and thus sum-DoF) optimality for non-intermittent 3WCs and its sum-DoF optimality for (node-)intermittent 3WCs. However, we show by example that in general some DoF tuples in the intermittent 3WC can only be achieved by adaptive schemes, such as decode-forward relaying. This shows that non-adaptive encoding is sufficient for the non-intermittent 3WC and for the sum-DoF of intermittent 3WCs, but adaptive encoding is necessary for the DoF region of intermittent 3WCs. Our work contributes to a better understanding of the fundamental limits of multi-way communication systems with intermittency and the impact of adaptation therein.

Degrees of Freedom of the Full-Duplex Asymmetric MIMO 3-Way Channel with Unicast and Broadcast Messages

In this paper, we characterize the total degrees of freedom (DoFs) of the full-duplex asymmetric multiple-input multiple- output (MIMO) three-way channel. Each node has a separate-antenna full-duplex MIMO transceiver with a different number of antennas, where each antenna can be configured for either signal transmission or reception. We study this system under two message configurations; the first configuration is when each node has two unicast messages to be delivered to the two other nodes, while the second configuration is when each node has two unicast messages as well as one broadcast message to be delivered to the two other nodes. For each configuration, we first derive upper bounds on the total DoF of the system. Cut-set bounds in conjunction with genie-aided bounds are derived to characterize the achievable total DoF. Afterward, we analytically derive the optimal number of transmit and receive antennas at each node to maximize the total DoF of the system, subject to the total number of antennas at each node. Finally, the achievable schemes for each configuration are constructed. The proposed schemes are mainly based on zero-forcing and null-space transmit beamforming. We show that the derived outer and inner bounds on the total DoF are tight for each message configuration.

Deterministic Quantum Key Distribution UsingTwo Non-orthogonal Entangled States

A deterministic quantum key distribution scheme usingtwo non-orthogonal entangled states is proposed. In theproposed scheme, communicators share key information byexchanging one travelling photon with two random and secretpolarization angles. The security of the distributed keyis guaranteed by three checking phases in three-way channel and thecommunicators' secret polarization angles.

The three-node wireless network: achievable rates and Cooperation strategies

We consider a wireless network composed of three nodes and limited by the half-duplex and total power constraints. This formulation encompasses many of the special cases studied in the literature and allows for capturing the common features shared by them. Here, we focus on three special cases, namely, 1) relay channel, 2) multicast channel, and 3) three-way channel. These special cases are judicially chosen to reflect varying degrees of complexity while highlighting the common ground shared by the different variants of the three-node wireless network. For the relay channel, we propose a new cooperation scheme that exploits the wireless feedback gain. This scheme combines the benefits of the decode-and-forward (DF) and compress-and-forward (CF) strategies and avoids the noiseless feedback assumption adopted in earlier works. Our analysis of the achievable rate of this scheme reveals the diminishing feedback gain in both the low and high signal-to-noise ratio (SNR) regimes. Inspired by the proposed feedback strategy, we identify a greedy cooperation framework applicable to both the multicast and three-way channels. Our performance analysis reveals the asymptotic optimality of the proposed greedy approach and the central role of list source-channel decoding in exploiting the receiver side information in the wireless network setting.