A proposal is put forward for an innovative method of multiple access, termed frequency Bank signal (FBS). The major advantage of FBS is that the error probability is almost non-sensitive to, either, the Doppler effect, separate signal delay or to the negative effect of reflected signals. In addition, FBS signals do not require special pilot or equalisation signals.

System free of channel problems inherent in changing mobile communication systems

Teknologi Long Term Evolution (LTE) dikembangkan dengan tujuan untuk mengurangi biaya yang dikeluarkan oleh pengguna maupun operator jasa telekomunikasi, memperluas daerah jangkauan, menambah kapasitas sistem, dan mengurangi delay. Dengan spesifikasi yang tinggi, LTE diharapkan mampu memberikan kemudahan pelanggan dalam mengakses layanan Voice over IP, Streaming, dan Video Conference. LTE diharapkan mampu memberikan layanan dengan besar throughput yang tinggi dan delay yang rendah. Padahal tidak semua user membutuhkan throughput yang sama besar namun yang dibutuhkan adalah kesesuaian pengendalian delay dan fairness index untuk setiap user dengan tetap memperhatikan batasan throughput. Untuk mendapatkan kinerja dan hasil yang maksimal tersebut pada LTE diperlukan sistem algoritma penjadwalan yang baik. Pada penelitian ini, dianalisis performansi LTE dengan parameter Delay, Packet loss, Throughput, dan Fairness Index menggunakan algoritma penjadwalan Proportional Fairness dan Log Rule pada LTE-Simulator dengan skenario menggunakan trafik VoIP, Video dan Best Effort. Hasil penelitian ini menunjukan bahwa penjadwalan algoritma Proportional Fairness lebih baik dalam menangani layanan VoIP, sedangkan algoritma Log Rule lebih baik dalam menangani layanan Video. Hal ini menandakan kedua algoritma ini sangat cocok digunakan untuk jaringan LTE dengan kondisi trafik layanan real-time, tetapi tidak untuk layanan non real-time seperti layanan Best Effort

/pdf/analisa-performansi-algoritma-penjadwalan-proportional-1vjj35ylm2.pdf

Analisa Performansi Algoritma Penjadwalan Proportional Fairness Dan Log Rule Dengan Skenario Multicell Pada Sistem 3GPP LTE

The present invention provides an ultra-wide band (UWB) system and method. In one embodiment, a transmitter of a low duty cycled ultra wide band (UWB) system includes a differential spreading encoder for encoding a phase of a bit sequence based on a reference bit sequence. The transmitter also includes a pulse generator for generating a number of pulses associated the bit sequence using the encoded phase of the bit sequence, where the number of pulses is equal to a length of the bit sequence. Moreover, the transmitter includes a DMPSK modulator for generating a modulated signal through modulating the number of pulses using a phase of a differential data symbol.

Ultra-wide band communication apparatus and method

An operation method of a terminal in a wireless communication system includes receiving a preamble sequence from a base station; estimating a UL channel between the terminal and the base station based on the preamble sequence; determining a first frequency region for transmitting a data signal and a second frequency region for transmitting a jamming signal in an entire frequency region of the UL channel based on a result of estimating the UL channel; and transmitting to the base station a UL control signal including identification information for identifying the first frequency region and the second frequency region.

Method and apparatus for physical layer security communication in wireless communication system

Disclosed in the embodiments of the present application are a data modulating and demodulating method, a data transmission method and node for multi-carrier system. The data modulating method including: selecting, by a transmitting node, corresponding waveform functions based on values of a first parameter, wherein the first parameter includes K values corresponding to K different waveform functions, respectively, and K is an integer greater than 1; and performing, by the transmitting node, using the selected waveform functions, modulation on time domain data sequences processed by Inverse Fast Fourier Transform (IFFT) to obtain a modulated data sequence. The first parameter may be configured by a base station for a UE. Also provided by the embodiments of the present application are a corresponding demodulation method and data transmission method and node.

Data modulation and demodulation method and data transmission method and node for multi-carrier system

In this article, I propose an innovative method of multiple access, known as Frequency Bank Signal (FBS). FBS combines the phase shift compensation used in the PAL-TV system, the OFDMA principle and the spread spectrum concept with Walsh functions.

The main advantage of using an FBS is that the error probability is almost non-sensitive to the Doppler Effect, separate signals delay and to the influence of fading. In addition, the FBS signal is free of special pilot, synchronization or equalization signals.

http://www.wseas.us/e-library/conferences/2006venice/papers/539-197.pdf

Wireless mobile communication systems without pilot signals

The present invention is directed to a method for canceling the Doppler shift, multi-path propagation, delays, and long time selective fading influences of phase and/or amplitude modulated signals carried by RF sub-carriers, without requiring pilot signals. The number of m=2n, over which individual datum is transmitted in each communication channel, is determined. Pairs of Walsh functions are selected from a Walsh-Hadamard matrix such that each function is not selected more than once. Each signal is partitioned to its I factor and Q factor and coding each I and Q factors of the signals by the pair functions. A corresponding phase and amplitude is allocated for each sub-carrier wherein the amplitude and phase values are determined by the data that is transmitted, the digital modulation scheme or inverse spectral transformation, and signs of both corresponding elements taken from the pair Walsh functions. Data is transmitted over the sub-carriers and received and the corresponding phases and amplitudes of all the received signals are obtained using spectral transformation. The received signals are decoded by changing signs of I and Q factors of the received signals in accordance with corresponding elements from the pair functions, used to decode said signals. The I and Q factors of received signals are summed separately, after changing signs of said I and Q factors of received signals, and each of the summations of I and Q factors is divided by m. The signal is reconstructed using said divided I and Q factors, by calculating its phase.

A wireless mobile communication system without pilot signals

This article examines the use of Orthogonal Frequency Division Multiple Access (OFDMA) method with pilot signals in cellular systems. The main goal of the investigation and simulation is to examine the Doppler effect influence on orthogonality disturbance in critical but real situations. The simulation results enable us to conclude that the influence of Doppler effect on pilot signals leads to an adverse effect instead of a beneficial one, and may perhaps be the main reason for mobile OFDMA system failure.

OFDMA Systems, Pilot Signals and Doppler Effect

This article puts forward an examination of using OFDMA method like WiMax for future cellular systems. The main goal of investigation and simulation is Doppler Effect influence on orthogonality disturbance in critical but real situations. The simulation results, allow coming to conclusion that Doppler Effect influence on pilot signals leads to BER increasing. The paper proposes Doppler Effect limiting values for pilot signals using and another solutions for decreasing Doppler Effect influences on OFDMA systems. One of possible solutions can be FBS method.

Doppler Effect Limiting Values in OFDMA Cellular Systems.

In this paper we investigate the performances of the Orthogonal Frequency Division Multiple Access (OFDMA) and Frequency Bank Signal (FBS) methods over High Altitude Platforms (HAPs) systems with different Doppler scales.

FBS is an enhanced OFDMA technique, which is capable to eliminate the negative effects of Doppler shifts even in extreme cases, such as non-uniform Doppler shifts across the OFDMA subcarriers. Our simulations show that HAP- OFDMA systems can work if frequency shift due to Doppler Effects is smaller than 2% of carrier frequencies separation. These conditions correspond to the frequency band of 2GHz and train velocity 120 km/h. FBS method allows increasing the permissible Doppler shift up to 6-8 %, hence enabling higher carrier frequency bands and higher speed vehicles.

http://www.wseas.us/e-library/conferences/2011/Cambridge/NEHIPISIC/NEHIPISIC-54.pdf

Boris Hill

Papers

Wireless mobile communication systems without pilot signals

A wireless mobile communication system without pilot signals

OFDMA Systems, Pilot Signals and Doppler Effect

Doppler Effect Limiting Values in OFDMA Cellular Systems.

HAPs special OFDMA technique for fast mobile radio systems