The capacity region of the multiple antenna (transmit and receive) broadcast channel is considered. We propose an outer bound to the capacity region by converting this nondegraded broadcast channel into a degraded one with users privy to the signals of users ordered below them. We extend our proof techniques in the characterization of the sum capacity of the multiple antenna broadcast channel t...

In this paper, a new analysis method of broadcast beamforming for a massive MIMO antenna array, targeting at the fifth generation mobile communication, is introduced. In order to solve the problem of narrow broadcast beam coverage, the element phase of massive MIMO antenna array is optimized using a method, which combines both numerical electromagnetic analysis method and global optimization al...

In our previous work, we presented a power-efficient algorithm called Greedy Perimeter Broadcast Efficiency (GPBE) algorithm exploiting broadcast efficiency using an omnidirectional antenna. We showed that with remarkably simple code complexity (not computational complexity), we could derive an algorithm which is comparable to Broadcast Incremental Power (BIP) in terms of the total transmit pow...

Employment of the multiple-antenna transmitters/receivers in communication systems is known as a promising solution to provide high-data-rate wireless links. In the multiuser environments, the problems of signaling and fairness for multi-antenna systems have emerged as challenging problems. This dissertation deals with these problems in several multi-antenna multi-user scenarios. In part one, a...

Employment of the multiple-antenna transmitters/receivers in communication systems is known as a promising solution to provide high-data-rate wireless links. In the multiuser environments, the problems of signaling and fairness for multi-antenna systems have emerged as challenging problems. This dissertation deals with these problems in several multi-antenna multi-user scenarios. In part one, a...

We characterize the sum capacity of the multiple antenna Gaussian broadcast channel by showing that the existing inner bound of Marton and the existing upper bound of Sato are tight for this channel. We exploit an intimate four-way connection between the multiple antenna broadcast channel, the corresponding point-to-point channel (where the receivers can cooperate), the multiple access channel ...

In this paper, we suggest enhanced broadcasting method, named 'BSART(Broadcasting with Selected Acknowledgement and Repeat Transmissions)' which reduces broadcast storm and ACK implosion on the mobile ad-hoc network with switched beam antenna elements that can enable bidirectional communication. To reduce broadcast storm, we uses DPDP(Directional Partial Dominant Pruning) method, too. To contro...

In wireless data networks, communication is particularly susceptible to eavesdropping due to its broadcast nature. Security and privacy systems have become critical for wireless providers and enterprise networks. This paper considers the problem of secret communication over the Gaussian broadcast channel, where a multi-antenna transmitter sends independent confidential messages to two users wit...

In this paper, we study the Minimum Latency Broadcast Scheduling (MLBS) problem in wireless sensor networks (WSNs). The main issue of the MLBS problem is to compute schedules with the minimum number of timeslots such that a base station can broadcast data to all other sensor nodes with no collisions. Unlike existing works that utilize the traditional omni-directional WSNs, we target the directi...

In this paper, the issue of broadcasting in mobile ad hoc networks (MANETs) is considered. A node equipped with directional antenna can divide the Omni directional transmission range into several sectors and turn some of them “on” for transmission. In the proposed scheme using a directional antenna, forwarding nodes selected locally need to transmit broadcast messages, only to the restricted se...