Title :
Effect of Control Delay in AMC in Asymmetric TDD Systems
Author :
Lynn, Nandar ; Takyu, Osamu ; Nakagawa, Masao ; Esmailzadeh, Riaz
Author_Institution :
Dept. of Inf. & Comput. Sci., Keio Univ., Yokohama
Abstract :
This paper evaluates downlink throughput performance affected by asymmetric slot allocation in time division duplex (TDD) systems that employ adaptive modulation and coding (AMC). By exploiting channel reciprocity TDD systems can utilize open loop channel estimation to adaptively change modulation and coding scheme (MCS) in AMC. However, control delay in AMC in asymmetric TDD systems is subject to time slot allocation formats. Large control delay in AMC leads to the selection of an inappropriate MCS. We present an analytical approach to calculate the probability of MCS level selection error in different channel conditions for different asymmetric time slot allocations. The results of numerical calculation are validated by the simulated results. Finally throughput performance affected by different TDD asymmetric formats is discussed based on respective MCS false selection probability in each time slot allocation format
Keywords :
adaptive modulation; channel estimation; delays; modulation coding; probability; time division multiplexing; AMC; adaptive modulation-coding; asymmetric TDD system; asymmetric time slot allocation; channel reciprocity; control delay; false selection probability; open loop channel estimation; time division duplex; Buffer storage; Channel estimation; Control systems; Delay effects; Downlink; Modulation coding; Open loop systems; Probability; Resource management; Throughput;
Conference_Titel :
Communication systems, 2006. ICCS 2006. 10th IEEE Singapore International Conference on
Conference_Location :
Singapore
Print_ISBN :
1-4244-0411-8
Electronic_ISBN :
1-4244-0411-8
DOI :
10.1109/ICCS.2006.301541
