This paper presents the behaviour of a turbo coding scheme when the symbol timing is not perfectly known. The algorithm for timing synchronization together with the theoretical Cramer Rao bound and the performance of an NDA ML synchronizer are presented. It is shown that synchronization can be achieved using the soft bit outputs of the turbo decoder without the need of using complex separate sy...

Space-time block codes provide substantial diversity advantages for multiple transmit antenna systems at a low decoding complexity. In this paper, we concatenate space-time codes with Convolutional Codes (CC), Turbo Convolutional codes (TC), Turbo BCH codes (TBCH), Trellis Coded Modulation (TCM) and Turbo Trellis Coded Modulation (TTCM) schemes for achieving a high coding gain. The associated p...

In a modern small sized passenger car fitted with a common rail diesel engine, turbo-lag is an important factor which hampers its performance. This paper discusses the basics of turbo-charger and VGT and some of the methods employed to reduce the turbo-lag in CRDI diesel engine. A novel turbocharger concept, approach to design, the control strategy and advantages of the concept are explained.

The mystery of belief propagation (BP) decoder, especially of the turbo decoding, is studied from information geometrical viewpoint. The loopy belief network (BN) of turbo codes makes it difficult to obtain the true “belief” by BP, and the characteristics of the algorithm and its equilibrium are not clearly understood. Our study gives an intuitive understanding of the mechanism, and a new frame...

The performances of turbo coded modulation using asymmetric turbo codes with transmit antenna diversity are analyzed. The component convolutional codes are considered to have memory 2 and 3, respectively, and their generator polynomials are both primitive and nonprimitive. The performances of asymmetric turbo coded modulation were evaluated performing simulations to obtain the bit error rate (B...

Turbo Trellis-Coded Modulation (TTCM) is a very promising approach for future communication systems. It combines the advantages of channel coding with multilevel signals and the powerful Turbo-Codes concept. In this paper we consider VLSI implementation aspects of TTCM. We show that techniques, known from binary Turbo-Decoders, can be applied to TTCM to reduce the implementation complexity sign...

We investigate the optimization of turbo-Brayton cycles for cooling current leads. Simple models of single stage current lead, two-stage current lead and two stage current lead coupled with a double stage turbo-Brayton cycle have been used to provide understanding about the issues and the tradeoffs. In addition, we discuss the possibility of using the heat exchanger in the turbo-Brayton system ...

This paper presents the FPGA hardware design of a turbo decoder for the cdma2000 standard. The work includes a study and mathematical analysis of the turbo decoding process, based on the MAX-Log-MAP algorithm. Results of decoding for a packet size of two hundred fifty bits are presented, as well as an analysis of area versus performance, and the key variables for hardware design in turbo decoding.

The paper starts with a short overview of channel coding and the reader is reminded the concept of convolutional encoding. Bottlenecks of the traditional approach are described and the motivation behind turbo codes is explained. After examining the turbo codes design more in detail, reasons behind their efficiency are brought out. Finally, a real-world example of the turbo code used in the thir...

This paper presents the behaviour of a turbo coding scheme when the synchronization parameters are not perfectly known. The algorithm for timing synchronization together with the theoretical Cramer Rao bound and NDA ML synchronizer are presented. It is shown that synchronization can be achieved using soft bit output of the turbo decoder without the need of using complex separate synchronizers p...