Studies have shown that transmit and receive diversity employing a combination of multiple transmit-receive antennas (given ideal channel state information (CSI) and independent fading between antenna pairs) will potentially yield maximum achievable system capacity. In this paper, the concept of a layered super-orthogonal turbo transmit diversity (SOTTD) for downlink directsequence code-divisio...

Interference cancellation (IC) is one identified key technology to enhance WCDMA uplink performance. The goal of this contribution is to highlight the relative uplink system capacity improvement available for WCDMA, especially in realistic typical urban radio environments when employing receiver implementations including realistic channel estimation, searcher, and so forth. The performance of t...

Classical feedback is defined here as the knowledge by the transmitter of the quantum state of the qubit received by the receiver. Such classical feedback doubles capacities of certain memoryless quantum channels without preexisting entanglement between transmitter and receiver. The increase in capacity, which is absent on classical memoryless channels, occurs because we can transform an entang...

The topic of this work is channel estimation for multi-input multi-output (MIMO) systems with very coarse signal quantization at the receiver. While coarse quantization of the received signal may only have a small to moderate impact on the channel capacity of MIMO systems, it is, however, necessary for the receiver to know the MIMO channel matrix. This motivates to study possible ways of estima...

Massive multiple-input multiple-output (MIMO) is becoming a key technology for future 5G cellular networks. Channel feedback for massive MIMO is challenging due to the substantially increased dimension of the channel matrix. This motivates us to explore a novel feedback reduction scheme based on the theory of principal component analysis (PCA). The proposed PCA-based feedback scheme exploits th...

In this paper we seek to identify the primary factors that determine the time-to-recovery of a network of DOCSIS-compliant cable modems (CM's). DOCSIS, which stands for Data-Over-Cable Service Interface Speci cations [6], is an emerging industry standard for data services over the cable TV infrastructure. According to the speci cation, individual cable modems must compete for access to the upst...

The superactivation of zero-capacity quantum channels makes it possible to use two zero-capacity quantum channels with a positive joint capacity for their output. Currently, we have no theoretical background to describe all possible combinations of superactive zero-capacity channels; hence, there may be many other possible combinations. In practice, to discover such superactive zero-capacity ch...

The qubit depolarizing channel with noise parameter η transmits an input qubit perfectly with probability 1− η, and outputs the completely mixed state with probability η. We show that its complementary channel has positive quantum capacity for all η > 0. Thus, we find that there exists a single parameter family of channels having the peculiar property of having positive quantum capacity even wh...

Recently, substantial attention has been paid to improve the spectral efficiency of communication setups using different spectrum sharing techniques. This paper aims to study the capacity of Rayleigh-fading spectrum sharing channels in the case where there is correlation between the fading channels. Assuming perfect channel state information, the channel capacity is obtained under both adaptive...

This paper proposes a packetized direct sequence code division multiple access (DS-CDMA) multimedia wireless communication system that allows for seamless interfacing to asynchronous transfer mode (ATM) broadband networks. The issue of reverse link power control is examined in the context of an indoor environment characterized by a slowly Rayleigh fading channel. Three algorithms are discussed:...