The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
For poor robustness issues of pitch detection of noisy speech, the improved pitch detection method combined with speech enhancement is proposed in this paper. Firstly, in order to reduce background noise and receive the clean speech relatively, we use the multi-band spectral subtraction and the masking properties of human auditory system to work on the noisy speech, and next use the energy and zero-crossing...
For the problem of Direct Sequence spread spectrum unbalance Quadrature Phase Shift Keying (DSSS/UQPSK) signal can't be detected easily, the method of the fourth-order cumulant detection is proposed in this paper. On the basis of the fourth-order cumulant of the Gaussian White Noise is equal to zero, Firstly, the paper analyzes the theory knowledge of direct sequence unbalance QPSK signal and the...
Owing to the frequency-selective fading channel with a carrier frequency of OFDM (orthogonal frequency division multiplexing) signal to noise ratio (SNR) estimation problem, we proposed SNR blind estimation method based on air carrier OFDM system. Due to the inconsistency between the oscillator and the received signal, the received signal will be with a certain deviation. The presence of frequency...
The diversity-multiplexing tradeoff (DMT) is one of the most important criteria to evaluate the performance of wireless relay networks. Previous work shows that, compared to decode-and-forward (DF) and estimate-and-forward (EF) relaying protocols, amplify-and-forward (AF) achieves the worst DMT and cannot reach the DMT upper bound. In this paper, we propose a new relaying protocol, called dynamic...
In this paper, we consider a dual-hop regenerative relay system consisting of one source node, one destination node and multiple relay nodes. All nodes are equipped with a single antenna except the destination node. We discuss two different relay selection strategies: 1) selection of the best relay; and 2) selection of all reliable relays. We investigate the optimal power allocation (PA) and relay...
Spectrum sensing plays a vital part in cognitive radio (CR) communication. In this paper, we consider a novel proactive sensing scheme that helps combat the hidden-node problem, while increasing certainty in the decision of spectrum occupancy. We extend this scheme by limiting the power of the probing signal used in carrying out proactive detection, with constraints set based on the interference threshold...
In this paper, we study the impact of imperfect channel state information at the transmitter and receiver (CSITR) on the diversity-multiplexing tradeoff in single-input multi-output (SIMO)/multi- input single-output (MISO) fading channels with two- way training. We consider two two-way training strategies: 1) the destination initiates the training, and 2) the source initiates the training. We show...
Two-way amplify-and-forward relaying is considered in this paper. We propose adaptive power allocation (PA) algorithms to maximize the instantaneous achievable rate and minimize the system outage probability, respectively. Both single- and multi-relay systems are considered. It is shown that the proposed adaptive PA algorithms significantly outperform the uniform PA algorithms. Furthermore, exploiting...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.