In this paper, a modified optimal power allocation scheme for different bits in turbo encoder has been proposed to improve the performance of Turbo Codes system in High Speed Downlink Packet Access (HSDPA) service. In a typical turbo code in HSDPA system, an encoder with code rate of 1/3 was used with bit repetition scheme or puncturing system to achieve code rate of 1/4. In this study, the aut...

The Intel® CoreTM i7 processor code named Nehalem has a novel feature called Turbo Boost which dynamically varies the frequencies of the processor’s cores. The frequency of a core is determined by core temperature, the number of active cores, the estimated power and the estimated current consumption. We perform an extensive analysis of the Turbo Boost technology to characterize its behavior in ...

A turbo coded cooperative orthogonal frequency division multiplexing (OFDM) with multiple-input multiple-output (MIMO) antennas scheme is considered, and its performance over a fast Rayleigh fading channel is evaluated. The turbo coded OFDM incorporates MIMO (2 × 2) Alamouti space-time block code. The interleaver design, and its placement always plays a vital role in the performance of a turbo ...

The key issue of applying Turbo codes is to find an efficient implementation of turbo decoder. This paper addresses the implementation of a simplified and efficient turbo decoder in field programmable gate array (FPGA) technology. A simplified and efficient implementation of a Turbo decoder with minor performance loss has been proposed. An integer Turbo decoder based on the standard 2’s complem...

In this paper, the receivers with adaptive equalizer and turbo decoder are investigated for orthogonal frequency division multiplexing-code division multiple access (OFDM-CDMA) systems in multipath channels. The de-spreading equalizer which combines de-spreading and equalization is used to mitigate the MAI and ISI. The stochastic gradient based LMS algorithm is used as the adaptive algorithm fo...

—In this paper, MIMO (Multiple-Input-Multiple Output) system based on turbo equalization techniques which LDPC (Low Density Parity Check) codes were outer code and STTC (Space Time Trellis Code) were employed as an inner code are studied. LDPC decoder and STTC decoder are connected through the interleaving and de-interleaving that updates each other's information repeatedly. On the receiver si...

This paper presents a new family of turbo codes called multi-non-binary turbo codes (MNBTCs) that generalizes the concept of turbo codes to multi-non-binary (MNB) parallel concatenated convolutional codes (PCCC). An MNBTC incorporates, as component encoders, recursive and systematic multi-non-binary convolutional encoders. The more compact data structure for these encoders confers some advantag...

Turbo codes enable high quality communication links by offering exceptional error correction capabilities. Turbo coding is proposed in the coming Universal Mobile Telecommunication Systems (UMTS) standard by the 3GPP for high data rates channels. Direct realization of the Turbo decoder algorithm in hardware encounters many challenges, such as algorithm complexity, large silicon area, high power...

AND TURBO CODES Javier Garcia-Frias and John D. Villasenor Electrical Engineering Department University of California, Los Angeles Abstract|Hidden Markov models have been widely used to statistically characterize sources and channels in communication systems. In this paper we will consider their application in the context of turbo codes. We will describe simpli ed techniques for modifying a dec...

nels was computed. Wiberg [3] in his dissertation has W e model the density of extrinsic information in iterative turbo decoders by Gaussian density functions. This model is verified by experimental measurements. We consider evolution of these density functions through the iterative turbo decoder as a nonlinear dynamical system with feedback. Iterative decoding of turbo codes and of serially co...