Using Markov model and the network simulator-NS, this paper studies the TCP throughput performance in wireless fading channel where the packets losses are always caused by high and burst errors. The results show that the burstiness in packet errors caused by slow multipath fading benefits Reno compared to i.i.d packet errors.
In this paper, a novel timing offset estimation algorithm of low complexity is presented, which needs a few pilots. The results of simulation prove that the system performance with timing offset correction is approximate to that over AWGN channel.
QIU Yan~1, QIN Sheng-ping~2, YUE Guang-xin~3 1.Qingdao Institute of Architecture and Engineering, Qingdao 266033, P.R. China
Recently, hosts of Medium Access Control （MAC） protocols for Ad hoc radio networks have been proposed to solve the hidden terminal problem and exposed terminal problem. However most of them take into no account the interactions between physical （PHY） system and MAC protocol. Therefore, the current MAC protocols are either inefficient in the networks with mobile nodes and fading channel or difficult in hardware implementation. In this paper, we present a novel media access control for Ad hoc networks that integrates a media access control protocol termed as Dual Busy Tone Multiple Access （DBTMA） into Orthagonal Frequency Division Multiplexing （ OFDM ） system proposed in IEEE 802.11 a standard. The analysis presented in the paper indicates that the proposed MAC scheme achieves performance improvement over IEEE 802.11 protocol about 25% -80% especially in the environment with high mobility and deep fading. The complexity of the proposed scheme is also lower than other implementation of similar busy tone solution. Furthermore, it is compatible with IEEE 802. 11a networks.
