Abstract Coherent rake reception of direct sequence code division multiple access (DS-CDMA) signals requires accurate channel estimation in a frequency-selective fading channel. In this paper, we study the channel estimation method using FFT/IFFT for coherent DS-CDMA mobile radio using the code-multiplexed pilot structure. This channel estimation method can provide a good tracking capability ag...

This paper explores and compares FER (Frame Error Rate) of a MAC (Medium Access Control) layer in the IEEE 802.11 a/g/n wireless LAN. It is evaluated under the fading wireless channel, using theoretical analysis method. It is analyzed by using the number of stations with both variable payload size and mobile speed on the condition that fading margin and transmission probability are fixed. Espec...

In this paper, we analyze the secure connectivity in Shotgun cellular systems (SCS: Wireless communication systems with randomly placed base stations) by Poisson intrinsically secure communication graph (IS-graph), i.e., a random graph which describes the connections that are secure over a network. For a base-station in SCS, a degree of secure connections is determined over two channel models: ...

A novel adaptively delayed retransmission scheme for SR ARQ in fading channel is proposed for wireless data communications, by which the link layer protocol and the physical channel are considered together for a successful deployment of effective error control strategies. Specifically, at link layer, when an information frame is corrupted, it is not retransmitted immediately but delayed for a d...

The third-generation universal mobile telecommunications system (UMTS) uses direct-sequence code division multiple access (DS-CDMA) to transmit data. DS-CDMA is well suited to transmit data over the multipath fading channel. The high signal bandwidth for the WCDMA system (5 MHz) allows the received signal to be split into distinct multipaths with high resolution. For the first generation of UMT...

The classic Costa’s “writing on dirty paper” capacity result establishes that full state pre-cancellation can be attained in the Gel’fand-Pinsker channel with additive state and additive Gaussian noise. This result holds under the assumption that perfect channel knowledge is available at both transmitter and receiver: such an assumption is not valid in wireless scenarios affected by fading and ...

In a mobile communication environment the channel is not time invariant and is slowly varying. This characteristic feature of the channel leads to a phenomenon called Fading. Fading channels induce rapid amplitude fluctuations in the received signal. If they are not compensated for then this will lead to serious performance degradation. In this paper simulations have been conducted to study the...

Channel estimation is an essential part of many detection techniques proposed for data transmission over fading channels. For the frequency selective Rayleigh fading channel an autoregressive moving average representation is proposed based on the fading model parameters. The parameters of this representation are determined based on the fading channel characteristics, making it possible to emplo...

This paper presents a spatial fading emulator for evaluating handset MIMO antennas in a cluster environment. The proposed emulator is based on Clarke’s model and has the ability to control RF signals directly in spatial domain to generate an accurate radio propagation channel model, which includes both uniform and non-uniform angular power spectra (APS) in the horizontal plane. Characteristics ...

This paper evaluates the performance of OFDM BPSK & -QPSK based system with and without channel estimation over Nakagami-m fading channels. Nakagami-m variants are generated by decomposition of Nakagami random variable into orthogonal random variables with Gaussian distribution envelopes. Performance of OFDM system in Nakagami channel has been reported here. The results yield the optimum value ...