In multiple-input multiple-output–orthogonal frequency division multiplexing (MIMO–OFDM) communications, the channel state information (CSI) of the forward link at each subcarrier is needed for precoder design at the transmitter to achieve the maximal diversity and/or multiplexing gains. In frequency division duplex (FDD) systems, the CSI needs to be estimated at the receivers and fed back to t...

Joint optimization of nonlinear precoders and receive filters is studied for both the uplink and downlink in a cellular system. For the uplink, the base transceiver station (BTS) receiver implements successive interference cancellation, and for the downlink, the BTS station pre-compensates for the interference with Tomlinson-Harashima precoding (THP). Convergence of alternating optimization of ...

To improve the QoS of best-effort based networks and accommodate heterogeneous receivers different solutions based on applying hierarchical transmission of data streams have been introduced. These solutions are based on multicasting a base layer which is received by all interested end systems. In addition, enhancement layers are transmitted that improve the quality of the base layer. Each recei...

Group membership regulation is a useful mechanism for multicast congestion control: RLM, RLC, FLID-DL, and WEBRC form a promising line of multi-group protocols where receivers provide no feedback to the sender but control congestion via group subscription. Unfortunately, the group subscription mechanism also offers receivers an opportunity to elicit self-beneficial bandwidth allocations. In par...

Collaborative beamforming (CBF) with a finite number of collaborating nodes (CNs) produces sidelobes that are highly dependent on the collaborating nodes' locations. The sidelobes cause interference and affect the communication rate of unintended receivers located within the transmission range. Nulling is not possible in an open-loop CBF since the collaborating nodes are unable to receive feedb...

Mobile ad hoc network is an autonomous system of mobile nodes characterized by wireless links. The major challenge in ad hoc networks lies in adapting multicast communication to several environments, where mobility is unlimited and failures are frequent. Reliable multicast delivery requires a multicast message to be received by all mobile nodes in the communication group. The recovery mechanism...

A critical problem faced by feedback-merger mechanisms is the lack of information that is discarded due to the hidden nodes in multicast trees. A node is said to be hidden from another if it is located in a sub tree that is a result from a fork in any upstream node. We propose in this paper the virtual layering scheme to avoid the problem caused by hiddennodes in multi-layered multicast video e...

In this article, we propose a new single-rate end-to-end multicast congestion control scheme called Explicit Rate Multicast Congestion Control (ERMCC) based on a new metric, TRAC (Throughput Rate At Congestion). ERMCC can be implemented only at the source and the receivers of the multicast tree. ERMCC achieves an O(1) memory complexity to maintain state information at source and receivers; requ...

This work considers the problem of mitigating information leakage between communication and sensing in systems jointly performing both operations. Specifically, a discrete memoryless state-dependent broadcast channel model is studied which (i) presence feedback enables transmitter to convey information, while simultaneously state estimation; one receivers treated as an eavesdropper whose should...