We consider the downlink rate control problem in a wireless channel. A dynamic programming optimization method is introduced to obtain optimal bit-rate/delay policy for packet transmission networks with fading channels. assume that base station capable of transmitting data packets different bit rates, R/sub 0/<R/sub 1/</spl middot//spl middot/<R/sub M-1/. It assumed symbol fixed system, and rates are achieved by choosing transmitted symbols from appropriate signal constellation (adaptive...

Recently, near-field communications (NFCs) have drawn great attention for the region expansion in context of extremely large-scale (XL) antenna arrays, tremendously high frequencies, and new types antennas trends. Considering distinctive spherical wave propagation model NFC, multiple-input multiple-output (MIMO) techniques, such as channel modelling estimation well hybrid beamforming technologies, recently undergone reevaluation redesign. Concurrently, NFC range continues to broaden,...

In this paper, we propose a framework to transmit multiple scalable video programs over downlink multiuser orthogonal frequency division multiplex (OFDM) networks in real time. The explores the scalability of codec and multidimensional diversity OFDM systems achieve optimal service objectives subject constraints on delay limited system resources. We consider two essential objectives, namely, fairness efficiency. Fairness concerns quality deviation among users who subscribe same service,...

Multiple-input multiple-output (MIMO) orthogonal-frequency-division-multiplexing (OFDM) systems employing coherent receivers crucially require channel state information (CSI). Since the multipath delay profile of channels is arbitrary in MIMO-OFDM systems, an effective estimator needed. In this paper, we first develop a pilot-embedded data-bearing (PEDB) approach for joint estimation and data detection, which PEDB least-square (LS) maximum-likelihood (ML) detection are employed. Then,...

A low-power parallel VLSI structure for DCT/IDCT is proposed. By treating the transformations as evaluation of Chebyshev series, and exploiting Backward Recursion (BCR), we can reduce total number multipliers (N+1 IDCT, 2N-2 DCT). The property BCR also used to compute through down-sampled even odd sequences. Since operation frequency sequences two times slower, speed penalty caused by low-voltage design be compensated at architectural level. required only 2N+1 IDCT 3N-3 DCT. Extension...

This paper evaluates the performance of data-bearing approach for pilot-embedding joint data detection and channel estimation in space-time (ST) coded MIMO systems. Performance measures, such as MMSE estimation, Cramer-Rao lower bound (CRLB), Chernoff's estimated-channel bit error rate (BER) ST codes, are explored to examine proposed scheme. The power allocation problem pilot parts is also addressed by optimizing probability-of-error upper-bound (PEUB) mismatched factor subject certain...

Transmitting multiple real-time encoded videos to users over wireless cellular networks is a key driving force for developing broadband technology. We propose new framework transmit users' video programs by MPEG-4 FGS codec downlink multicode CDMA in real time. The proposed jointly manages the rate adaptation of source and channel coding, code allocation, power control. Subject limited system resources, such as number pseudo-random codes maximal transmission, we develop an adaptive scheme...

A real-time video conferencing framework is proposed for multiple pairs by jointly considering the uplink and downlink conditions within IEEE 802.11 networks. We formulate this system so as to minimize maximal end-to-end expected distortion received all users selecting PHY modes transmission time. Compared with strategy of individually optimizing downlink, outperforms 3.67-8.65 dB average PSNR among users.

A dynamic programming optimization method is used to obtain the optimal rate control policy in a wireless network with fading channel. In it assumed that base station capable of transceiving data packets at two rates, either R/sub h/ or l/ (R/sub h/>R/sub l/). An derived which jointly minimizes transmission delay and number switchings network. Numerical results indicate by sacrificing only 1% quality terms average one can achieve more than 50% reduction switching load Our analytical as well...

We address the problem of characterizing performance space-time modulation in time-correlated fading environment. show that signals square size achieving full diversity quasi-static channels can also achieve channels, irrespectively time correlation matrix. generalize notion product to include effect temporal correlation.

We introduce a family of square root free and division rotation based algorithms. Our approach suggests new perspective the Q R decomposition (QRD) algorithms leads to considerable reduction circuitry complexity time delay in associated architectures. The optimal residual weight ext:raction for recursive least squares (RLS) problem are considered this paper. systolic structures that described very promising, since they involve less computational from known date make VLSI implementation more...

Multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) is one prominent communication system for realizing high speed data transmission services. One critical issue such systems channel estimation. In this paper, we first develop a pilot-embedded data-bearing (PEDB) approach joint estimation and detection. Then propose least square (LS) FFT-based estimator by employing the concept of to improve performance PEDB-LS Also, effects model mismatch error when...

The time-recursive computation has been proved as a particularly useful tool in real-time data compression and transform domain adaptive filtering, with applications the areas of audio, radio, sonar, video. An architectural framework for parallel is proposed. authors consider class linear operators that consists discrete time, time invariant, compactly supported, but otherwise arbitrary kernel functions. They define shift property reveal its relation implementation. potential proposed...

This paper presents a new parallel transmission framework for reliable multimedia data over spectrally shaped channels using multicarrier modulation. We propose to transmit source layers of different perceptual importance in parallel, each occupying number subchannels. New loading algorithms are developed efficiently allocate the available resources, e.g. transmitted power and bit rate, subchannels according they transmit. Instead making error rate all equal as most existing algorithms,...