A novel multiuser code division multiple access (CDMA) channel estimator based on genetic algorithm is considered which estimates the fading channel impulse response coefficients of all the users. Furthermore, the optimum multiuser detector, based on the maximum likelihood (ML) rule, is developed in order to identify the transmitted data sequence. As is demonstrated in simulation results, the p...

Abstract An adaptive prediction iterative channel estimation is proposed for the MC−CDMA signal reception in a frequency selective fading channel. Adaptive prediction filtering is incorporated into iterative channel estimation process and the filter tap coefficients are adaptively updated according to changes in the propagation environment. For channel estimation, the pilot MC-CDMA symbol is pe...

A recent work explicitly models the discontinuous motion estimation problem in the frequency domain where the motion parameters are estimated using a harmonic retrieval approach. The vertical and horizontal components of the motion are independently estimated from the locations of the peaks of respective periodogram analyses and they are paired to obtain the motion vectors using a procedure pro...

—In cognitive radio network the primary channel information is beneficial. But it can not be obtained by direct channel estimation in cognitive system as pervious methods. And only one possible way is the primary receiver broadcasts the primary channel information to the cognitive users, but it would require the modification of the primary receiver and additional precious spectrum resource. Coo...

In this paper, a new method to estimate the parameter for turbo decoding using the maximum a posteriori probability (MAP) algorithm is proposed for a turbo code in a Rayleigh fading channel with imperfect channel estimation. This parameter is called the channel reliability factor and is related with the channel SNR. For channel estimation, pilot symbol assisted modulation (PSAM) is used and the...

In this paper, we investigate channel estimation techniques for wireless receivers. Channel estimation is important for wireless applications because a wireless channel has fading characteristics and time varying impulse response. OFDM is a multi-carrier modulation technique wherein we use a set of orthogonal sub-carriers. OFDM divides the entire frequency band into several sub bands. The sub-c...

In this paper, a novel noise reduction method using hybrid noise estimation technique and post-filtering is proposed to suppress both localized and non-localized noise components which can not be dealt with by the traditional methods [2][3][4]. To do this, a hybrid noise estimation approach is proposed by combining our previously constructed multichannel noise estimation approach and a single-c...

The conventional pilot-aided channel estimation schemes use the fixed number of pilots to estimate the channel. In this paper, the channel estimator exploits reliable decision feedback symbols as quasi-pilots. This new channel estimation scheme is commercially attractive without additional hardware in the receiver using DSP chips for the OFDM systems.

A channel delay can be estimated by evaluating the channel response to a deterministic signal. In the frequency domain, a maximum likelihood delay estimator which accounts for colored Gaussian measurement noise can be formulated. A procedure that allows fast estimation of the channel delay is proposed, in case a low-pass deterministic signal is applied to the channel. Keywords—Fractional delay;...

This paper investigates the performance gain for pilot-aided channel estimation in the uplink of multiuser OFDM mobile radio systems, when array antennas are applied at the receivers. The application of array antennas allows the exploitation of directional information of the desired and the undesired signals at the receivers based on the array geometry and the directions of arrival of the consi...