Performance Bounds for Bi-Directional Coded Cooperation Protocols

In coded bi-directional cooperation, two nodes wish to exchange messages over a shared half-duplex channel with the help of a relay. In this paper, we derive performance bounds for this problem for each of three protocols. The first protocol is a two phase protocol were both users simultaneously transmit during the first phase and the relay alone transmits during the second. In this protocol, our bounds are tight and a multiple-access channel transmission from the two users to the relay followed by a coded broadcast-type transmission from the relay to the users achieves all points in the two-phase capacity region. The second protocol considers sequential transmissions from the two users followed by a transmission from the relay while the third protocol is a hybrid of the first two protocols and has four phases. In the latter two protocols the inner and outer bounds are not identical, and differ in a manner similar to the inner and outer bounds of Cover's relay channel. Numerical evaluation shows that at least in some cases of interest our bounds do not differ significantly. Finally, in the Gaussian case with path loss, we derive achievable rates and compare the relative merits of each protocol in various regimes. This case is of interest in cellular systems. Surprisingly, we find that in some cases, the achievable rate region of the four phase protocol sometimes contains points that are outside the outer bounds of the other protocols.Comment: 15 page

Hallyu and the Traditional Cultural Genes of Korea

Since the year 2000, South Korea has been the propagator of the Hallyu (Korean Wave) that has spread across the world, demonstrating the country’s cultural potential. The subject of Hallyu can be approached from several perspectives, first by identifying its origins, current status, and trends by genre; by looking at its effects and the measures that can sustain the Hallyu phenomenon; and also by examining Hallyu trends by country. This paper analyzes Korea’s traditional cultural genes that affected the creation and spread of Hallyu from a humanistic point of view. The three factors for this analysis are: i) community and courtesy, ii) dynamics and excitement, and iii) intuition and harmony. This study is expected to deepen the understanding of the relation between Hallyu and Korean traditional cultural resources