Results 1 - 10 of 8,073

MIMO systems with adaptive modulation

by Zhendong Zhou, Student Member, Branka Vucetic, Mischa Dohler, Yonghui Li - IEEE Transactions on Vehicular Technology , 2005
"... Abstract—Adaptive modulation (AM) schemes in multiple in-put multiple output (MIMO) systems with a perfect or imperfect channel state information (CSI) at both the transmitter and re-ceiver were investigated. Under an average transmit power and instantaneous bit error rate (BER) constraint, the tran ..."
Abstract - Cited by 27 (0 self) - Add to MetaCart
Abstract—Adaptive modulation (AM) schemes in multiple in-put multiple output (MIMO) systems with a perfect or imperfect channel state information (CSI) at both the transmitter and re-ceiver were investigated. Under an average transmit power and instantaneous bit error rate (BER) constraint

Adaptive Modulation over Nakagami Fading Channels

by Mohamed-Slim Alouini, Andrea Goldsmith , 1998
"... We first study the capacity of Nakagami multipath fading (NMF) channels with an average power constraint for three power and rate adaptation policies. We obtain closed-form solutions for NMF channel capacity for each power and rate adaptation strategy. Results show that rate adaptation is the key to ..."
Abstract - Cited by 147 (17 self) - Add to MetaCart
delay. We also analyze the impact of time delay on the BER of adaptive M-QAM. Keywords Link Spectral Efficiency, Adaptive Modulation Techniques, and Nakagami Fading. I. Introduction The radio spectrum available for wireless services is extremely scarce, while demand for these services is growing at a

A Rate-Adaptive MAC Protocol for Multi-Hop Wireless Networks

by Gavin Holland, Nitin H. Vaidya, Paramvir Bahl , 2001
"... Wireless local area networks (W-LANs) have become increasingly popular due to the recent availability of affordable devices that are capable of communicating at high data rates. These high rates are possible, in part, through new modulation schemes that are optimized for the channel conditions bring ..."
Abstract - Cited by 484 (5 self) - Add to MetaCart
Wireless local area networks (W-LANs) have become increasingly popular due to the recent availability of affordable devices that are capable of communicating at high data rates. These high rates are possible, in part, through new modulation schemes that are optimized for the channel conditions

Adaptive Modulation for Fading Channels

by Nilo Casimiro Ericsson - Globecom99, Rio de Janeiro , 1999
"... In future packet based wireless communication systems, transmission in the downlink will often dominate the traffic load. High bit-rate applications like WWW-browsing, file transfer, and full motion video will impose strong requirements on the system capacity. An obstacle in this context is the time ..."
Abstract - Cited by 2 (1 self) - Add to MetaCart
is the time-variability of the channel: For mobile users, frequently occuring fading dips will cause unnecessary, and capacity degrading, retransmissions. To achieve a high throughput also over fading channels, adaptive methods for adjustment of e.g. the modulation alphabet, and the coding complexity, can

Combining Adaptive Modulation And Coding With

by Truncated Arq Enhances, Qingwen Liu, Shengli Zhou, Georgios B. Giannakis
"... We develop a cross-layer design which combines adaptive modulation and coding (AMC) at the physical layer with a truncated auto repeat request (ARQ) protocol at the data link layer, in order to maximize spectral efficiency under prescribed delay and performance constraints. We derive the achieved sp ..."
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We develop a cross-layer design which combines adaptive modulation and coding (AMC) at the physical layer with a truncated auto repeat request (ARQ) protocol at the data link layer, in order to maximize spectral efficiency under prescribed delay and performance constraints. We derive the achieved

Adaptive Modulation and Coding Rate

by unknown authors
"... Abstract — Wireless communication is observing a fast development in today’s communication era. A poorly designed path can result in periodic system outages, resulting in increased system latency, decreased throughput, or worst case, a complete failure of the system. Planning a good, stable and reli ..."
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and also to bring lot of applications. Our primary design objective in this paper is to minimize the error probability of a LTE system and to bring the spectrum efficiency through a process known as adaptive modulation and coding rate. LTE normally uses OFDM as its technology and we are going to implement

Does fast adaptive modulation always outperform slow adaptive modulation

by Laura Toni, Andrea Conti, Senior Member - IEEE Trans. Wireless Commun , 2011
"... Abstract—Link adaptation techniques are important modern and future wireless communication systems to cope with quality of service fluctuations in fading channels. These techniques require the knowledge of the channel state obtained with a portion of resources devoted to channel estimation instead o ..."
Abstract - Cited by 2 (1 self) - Add to MetaCart
of data and updated every coherence time of the process to be tracked. In this paper, we analyze fast and slow adaptive modulation systems with diversity and non-ideal channel estimation under energy constraints. The framework enables to address the following questions: (i) What is the impact of non

Adaptive Modulation for Multiple Antenna Channels

by June Chul Roh, Bhaskar D. Rao
"... We consider the use of adaptive modulation scheme for multiple transmit and multiple receive antenna system with instantaneous channel information known to both the receiver and the transmitter. We derive an efficient bit allocation algorithm which maximizes the transmission rate for a given transmi ..."
Abstract - Cited by 5 (0 self) - Add to MetaCart
We consider the use of adaptive modulation scheme for multiple transmit and multiple receive antenna system with instantaneous channel information known to both the receiver and the transmitter. We derive an efficient bit allocation algorithm which maximizes the transmission rate for a given

Adaptive Modulation And Scheduling For Fading Channels

by Nilo Casimiro Ericsson , 1999
"... In future packet based wireless communication systems, transmission in the downlink will often dominate the traffic load. High bit-rate applications like WWW-browsing, file transfer, and full motion video will impose strong requirements on the system capacity. An obstacle in this context is the time ..."
Abstract - Cited by 1 (0 self) - Add to MetaCart
is the time-variability of the channel: For mobile users, frequently occurring fading dips will cause unnecessary and capacity degrading retransmissions. To achieve a high throughput also over fading channels, adaptive methods for adjustment of e.g. the modulation alphabet, and the coding complexity, can

ABSTRACT Adaptive Modulation for Fading Channels

by unknown authors
"... In future packet based wireless communication systems, transmission in the downlink will often dominate the traffic load. High bit-rate applications like WWW-browsing, file transfer, and full motion video will impose strong requirements on the system capacity. An obstacle in this context is the time ..."
Abstract - Add to MetaCart
is the time-variability of the channel: For mobile users, frequently occuring fading dips will cause unnecessary, and capacity degrading, retransmissions. To achieve a high throughput also over fading channels, adaptive methods for adjustment of e.g. the modulation alphabet, and the coding complexity, can
Results 1 - 10 of 8,073