In the downlink of a multi-user MIMO (Multiple Input Multiple Output) communication system where each user has an arbitrary QoS requirement, intelligent algorithms are needed to choose transmit vectors. Here we present a new method of choosing transmit vectors that minimizes total transmitted power. The approach is based on previous iterative interference balancing algorithms, but it is initial...

Tricone bits are currently less commonly used as compared with PDC bits. mainly in drilling difficult geotechnical conditions and blasthole open pit mines. The main disadvantage of tricone is the relatively short life. cause age limit failure retaining ball bearing due to destruction raceway journal shoulder under high contact bending stresses. Based on provisions similarity theory, physical mo...

This thesis considers the joint design of bit loading, precoding and receive filters for a multiple-input multiple-output (MIMO) digital communication system. Both the transmitter and the receiver are assumed to know the channel matrix perfectly. It is well known that, for linear MIMO transceivers, orthogonal transmission (i.e., diagonalization of the channel matrix) is optimal for some criteri...

Discrete multi-tone (DMT) based digital subscriber loop (DSL) modems must allocate power and information bits to the discrete tones for quadrature amplitude modulation. The bitallocation (also referred to as bit-loading) algorithms in the literature are designed for modems that operate in the simplex mode in which the upstream and downstream signals use nonoverlapping frequency bands. However, ...

Cooperative communication is a promising technique for wireless communication systems where wireless nodes cooperate together in transmitting their information. Such communication transmission technique, which realizes the multiple antenna arrays in a distributed manner over multiple wireless nodes, succeeds in extending the network coverage, increasing throughput, improving both link reliabili...

In this paper, image transmission in underwater channels is considered. The images are encoded with forward error correction using an unequal error protection technique together with the Reed-Solomon codes and dynamic bit-rate allocation before transmitted. This paper proposes a novel rate allocation scheme for efficient image bit stream transmission in underwater acoustic channels with optimum...

The orthogonal frequency division multiplexing (OFDM), which has high spectral efficiency, is an attractive solution for silicon photomultiplier (SiPM)-based optical wireless communication (OWC) systems to boost data rates. However, the currently available SiPMs are not optimized implementing OFDM receiver. Incorporating different types of SiPM at receiver results in rates same condition. There...

Sprite coding, which can increase the coding efficiency of backgrounds greatly, is a novel technology adopted in MPEG-4 object-based coding. Due to the geometric transformation applied to each nonreference frame in the procedure of sprite coding, the generated sprite is distorted and the available view angles relative to the reference frame are restricted. These problems can be resolved by usin...