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This paper presents a novel and cost effective method to be used in the optimization of the Gaus-sian Frequency Shift Keying (GFSK) at the receiver of the Bluetooth communication system. The proposed method enhances the performance of the noncoherent demodulation schemes by improving the Bit Error Rate (BER) and Frame Error Rate (FER) outcomes. Lin...
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... Nonetheless, this research associated with new wireless seniors where the IEEE 802.15 signal has numerous indoor interference with IEEE 802.11 signal since both standards serving under the same frequency range 2.4 GHz. In [2], the performances of a Bluetooth system with a linear Kalman filter (KF), two other types of nonlinear KFs, extended Kalman filter (EKF), and an unscented Kalman filter (UKF) were compared. The results indicated that the Gaussian frequency shift key (GFSK) did not respond to the linear common filter due to its nonlinear modulation scheme. ...
... Therefore, [2] confirms that the UKF delivers a satisfactory result according to the estimated initial state measurements. In addition, the phenomenon of multipath fading has turned more prevalent in Bluetooth connections, as Bluetooth systems are widely applied in the field of voice transmission currently. ...
This study proposes a novel signal detection and modulation optimization scheme using the unscented Kalman filter (UKF) for the Bluetooth voice communication system for the indoor noise environment at Oakland University. It is designed for filtering received signals at the front-end of the receiver stage and established to be robust due to the usage of UKF. The UKF model is capable of handling modulated waveforms represented by the state-space model to reduce the non-Gaussian noise over a multipath fading channel. Moreover, this novel work addresses the characterization of the fading channel with typical non-Gaussian noise, which can be applicable in Bluetooth systems with 802.11b (Wi-Fi) standard interference. The simulation results are used to calculate the bit error rate and frame error rate. Keywords-Unscented Kalman Filter, Signal to noise ratio, Bit Error Rate, Gaussian frequency shift key.
... OFDM is computationally efficient by using FFT techniques [6] to implement the modulation and demodulation functions. There has been a tremendous amount of work on modulation/demodulation optimization using different types of estimators such as a Kalman filter [7] [8]. The OFDM system forms the basis for 4G wireless communication systems. ...
We present in this paper a method for enhancing equalization of a dynamic channel. A dynamic channel is characterized and modeled by a high relative velocity between transmitter and receiver and fast changes of environment conditions for wave propagation. Based on Jakes model, an auto-regressive model (AR) [1] for such a dynamic system, i.e., a time variant channel is developed. More specifically, the enhanced equalization method we are proposing is a combination of a multi-stage time and frequency domain equalizer with a feed-forward loop. The underlined wok presents a unified approach to the equalization method that employs both time and frequency domains data to enhance the equalization scheme. In an OFDM system, the channel coefficients for each tap, in time domain for consecutive blocks, are partially independent thus correlated. Such correlation can improve the channel estimation if it is taken into account. The method in this paper enhances the performance of equalization by dynamically selecting the number of previous OFDM symbols based on the Doppler frequency. In order to decrease the complexity of the system model, we utilize the autocorrelation and Doppler frequency to dynamically select the previous OFDM symbols that will be stored in the memory. In addition to deriving earlier results in a unified manner, the approach presented also leads to enhanced performance results without imposing any restrictions or limitations on the OFDM system such as increasing the number of pilots or cyclic prefix.
Abstract— Nowadays electronics gadgets are playing important role in day to day life. These gadgets are becoming popular due to their ease of use, fast recognition and wireless connectivity, interoperability at extremely low cost. These important abilities leads to increasing temptation to use in short range data and voice communication. Such applications speed of operation, coverage and frequency range are the major aspect. in This paper focuses on issues such as bit error rate and throughput performance of Bluetooth in the heterogeneous environment. Higher data rate requirement of fast consumer electronic devices can be achieved by employing higher modulation schemes. By changing the modulation techniques of Bluetooth, BER and throughput are calculated in presence of wireless LAN. From the results obtained it can be concluded, that Bluetooth works satisfactorily in heterogeneous environment with GFSK modulation technique, but to increase throughput, higher level modulation techniques has to incorporate at the cost of Eb/No.
