Adaptive modulation and MIMO coding for broadband wireless data networks

Abstract

Link adaptation techniques, where the modulation, coding rate, and/or other signal transmission parameters are dynamically adapted to the changing channel conditions, have recently emerged as powerful tools for increasing the data rate and spectral efficiency of wireless datacentric networks. While there has been significant progress on understanding the theoretical aspects of time adaptation in LA protocols, new challenges surface when dynamic transmission techniques are employed in broadband wireless networks with multiple signaling dimensions. Those additional dimensions are mainly frequency, especially in multicarrier systems, and space in multiple-antenna systems, particularly multiarray multiple-input multiple-output communication systems. In this article we give an overview of the challenges and promises of link adaptation in future broadband wireless networks. We suggest guidelines to help in the design of robust, complexity/cost-effective algorithms for these future wireless networks.

Optimized Channel Utilization in Multi-carrier Wireless Mobile Networks

“…We use the MCS capacity levels: [ ½½ ¾ ½ ½ ¾¾ ¾ ¾℄ (in kb/s) as outlined in the EGPRS modulation and coding schemes and peak data rates in [1].…”

“…This is suitable for duplex communication, since the transmission parameters have to be adapted using some form of two-way transmission [5,1].…”

“…Fast adaptation increases the number of mode-change messages transmitted over the channel, consuming bandwidth, and time resources [1]. While many aspects of scheduling transmissions over time-varying wireless channels have been studied (see, for example, [2][3][4] and the references therein), the penalty induced by LA has not been considered.…”

“…While many aspects of scheduling transmissions over time-varying wireless channels have been studied (see, for example, [2][3][4] and the references therein), the penalty induced by LA has not been considered. Moreover, predicting the future channel quality may also consume significant amount of system resources (e.g., time, bandwidth and power), since it may involve transmission of training-sequences, pilot tones, or feedback messages carrying the CSI [1]. Naturally, the additional cost and complication of predicting CS and LA increases with the desired prediction accuracy.…”

[Invited Paper] Adaptive Configuration of Forward Channels for Terminal Collaborative Reception

“…Since user data rate gets higher in the next generation wireless communication systems, frequency utilization efficiency will become more important. Many techniques have been proposed to raise frequency utilization efficiency, e.g., adaptive modulation and coding (AMC) 1) , and multiple input and multiple output (MIMO) 2) . Distributed antenna concept, which is regarded as a type of MIMO, has also been proposed for the next generation mobile communication 3)4) .…”