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Location estimation based on received signal strength (RSS) in WLAN environment is an attractive method for indoor positioning system. Unfortunately, due to the explicit nonlinearity and uncertainty of RSS signal, the traditional approaches always fail to deliver good location accuracy. This paper presents a novel positioning algorithm with kernel direct discriminant analysis (KDDA). We deploy the...
This paper proposes the optimal K nearest neighbors (KNN) positioning algorithm via theoretical accuracy criterion (TAC) in wireless LAN (WLAN) indoor environment. As far as we know, although the KNN algorithm is widely utilized as one of the typical distance dependent positioning algorithms, the optimal selection of neighboring reference points (RPs) involved in KNN has not been significantly analyzed...
Cooperative communications is widely used to share the resources of different nodes, and achieve spatial diversity gain in multi-user network. The node which is chosen as cooperative node (cluster-head), consumes more transmit power for other nodes than itself. Because of this, traditional algorithm results in uneven power distribution. In this paper, we propose a new algorithm called weighted clustering...
Indoor WLAN based positioning system required the use of a Radio-map to make the current received signal strength related to specific locations. However, the signal strength measurements are time consuming and expensive. This paper presents a Radio-map interpolating algorithm and compares the localization accuracy of measured Radio-map with interpolated Radio-map. The results presented that, although...
This paper considers the cooperative schemes where the source, relay and the destination are all multi-antenna terminals. Zero-forcing equalization and maximum ratio combining technique are employed in this scheme. We extend the classical selection relaying into the multi-antenna setup. Based on a predefined threshold, the source decides to cooperate only when it needs help. The source picks only...
In modern GNSS, new signal modulations are adopted to satisfy the demand for higher performance service. Based on the composite structure of Galileo E1 signals, which introduces data and pilot channels, some joint strategies are investigated for the acquisition block. Two typical algorithms are Noncoherent Combining (NCC) and Coherent Combining (CC). However, for the longer spreading sequence, the...
Unscented Kalman filter (UKF) based methods have been developed for the tracking of GPS L1 signal. Optimal Kalman filtering theory makes it possible to maintain locking with large Doppler frequency shift when the receiver works in high dynamic environment. A novel UKF based carrier tracking loop with high accurate tracking performance is put forward, where a frequency fast pull-in technology is performed...
Cooperative communications exploit the spatial diversity inherent in multiuser system by allowing cooperation among users having a wide range of channel qualities. How to search the cluster-head and its member relay nodes to cooperate is important. Since nodes are coming into or out of the clusters time to time, the network topology is perturbed and the reconfiguration of the network is unavoidable...
There has been an increasing attention on cooperative diversity, which is a method to allow a single-antenna mobile to share other mobiles' antennas and thus achieve transmit diversity. The use of multiple-antennas, however, has been identified as a certain trend for high-rate transmissions over wireless channel. In this paper, we investigate the uplink performance of a single-relay cooperative scenario...
2-dimensional (2D) block spread CDMA makes it possible to achieve multiple-access interference (MAI) free uplink transmission with low-complexity single-user detection and therefore is very attractive. In this paper, we propose a code assignment algorithm for 2D block spread CDMA uplink in multi-cell systems. It is shown by the computer simulation that in the frequency-selective fading channel, the...
This paper presents a wireless local area networks (WLAN) indoor positioning method based on adaptive neurofuzzy inference system (ANFIS), and improves the problem of decreased positioning accuracy caused by non-line-of-sight dominated transmission in commonly used indoor positioning systems effectively through the fingerprint method. First of all, the paper analyzes the design principles and mathematical...
In order to efficiently utilize the limited transmit power and frequency resource in single-user OFDM systems, intense research interest has focused on new algorithms on resource allocation. Rules and algorithms of resource allocation are first introduced in this paper. Then we propose another algorithm for resource allocation in order to utilize channel bandwidth and to reach the channel capacity...
The presence of the multi-access interference (MAI) limits the uplink performance of code division multiple access (CDMA). 2-dimensional (2D) block spread CDMA makes it possible to achieve MAI free uplink transmission while obtaining the frequency diversity gain by using low-complexity single-user frequency-domain equalization (FDE). To further improve the uplink transmission performance, the transmit...
To minimize transmitting power, an adaptive resource allocation algorithm is proposed for multi-user multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) downlink with correlated channels, which, based on the user’s grouping according to their spatial correlations, combines the shared manner and the exclusive manner to allocate sub-carriers. Between different groups...
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