The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This letter addresses the problem of feedback load reduction for opportunistic multicast scheduling (OMS) in OFDM-based systems. We investigate two scenarios, multicast service with large group size and multicast service with small group size, and derive two practical schemes respectively. The superiorities of the proposed schemes are: 1) no precise knowledge of the wireless fading channel is required,...
To reduce the feedback load of OFDM-based wireless multicast systems, an opportunistic feedback scheme (OFS) is proposed. OFS aims to only feed the key channel gains that can significantly affect the system throughput back to the base station (BS). By mathematical derivation, the key channel gains are proved to belong to a channel gain interval, which can be estimated by a proposed statistical method...
In conventional multicast scheme (CMS), the total throughput of multicast group is constrained by the user with the worst channel quality. In order to overcome this problem of limited throughput, we consider a resource allocation algorithm based on layered coding, when a limited feedback scheme is considered. A novel subcarrier and power algorithm is exploited for targeting the maximum throughput...
In this paper, we consider a multi-antenna wireless multicast system with multiple multicast groups. The problem of resource allocation with downlink precoding for the multicast systems is studied, assuming the channel state information between transmit and all the receivers is available at the transmitter. Specifically, we formulate an optimization problem to maximize the system throughput given...
In this paper, we investigate resource allocation issue in OFDM-based wireless multicast system and joint subcarrier and power allocation scheme is proposed. The optimal solution of the combinable allocation has high computational complexity, so the solution is divided into two steps. In the first step, the subcarriers are allocated to the multicast services, and all the users that have subscribed...
In this paper, we investigate resource allocation issue in OFDMA-based decode-and-forward cooperative networks and propose joint subcarrier and power allocation schemes. The optimal solution of this combinable allocation has high computational complexity, so we divide our solution into two steps. The first step is to distribute subcarriers to relays and destination under the assumption of equal power...
To avoid inter-cell interference effectively and to improve the performance of cell-edge users, a novel cellular architecture, termed Cellular Architecture Based on Sector Relay (CASR), is proposed in this paper, and two frequency planning schemes based on CASR are investigated. In CASR, fixed relays equipped with directional antennas are located at the vertex of the hexagonal cell for sectorization,...
In this paper, a two-hop amplify-and-forward cooperative diversity system using OFDM modulation was considered. We proposed an associated waterfllling power allocation scheme under separate power constraints at source and relay, which allocated source and relay power in an associated fashion. The scheme first allocated power to subcarriers uniformly, then gave an approximate equivalent channel gain...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.