In this paper we propose a new method to implement turbo codes over fading channels by extending the idea of turbo DPSK [3] to include turbo outer codes. An analytical tool has been developed to estimate the performance of extended turbo DPSK. A simulation study shows that extended turbo DPSK performs worse than BPSK modulated turbo codes with coherent detection. The energy inefficiency of exte...

A turbo code codec is implemented as a portion of a modem in a software radio. The performance of this software radio is tested in a Monte Carlo simulation and on a hardware testbed. The codec uses two punctured rate 1/2 constituent codes and a 16383-bit pseudo-random interleaver to produce a net rate ~1/2 turbo code. The modem generates a binary phaseshift keyed modulation on a 200 kHz carrier...

The convergence rate of LDPC decoding is comparatively slower than turbo code decoding: 25 LDPC iterations versus 8-10 iterations for turbo codes. Recently, Mansour proposed a ‘turbo-schedule’ to improve the convergence rate of LDPC decoders. In this letter, we first extend the turbo-scheduling principle to the check messages. Second, we show analytically that the convergence rate of both turbo...

A new code construction namely woven turbo codes, is presented , which is a variation of woven convolutional codes. Parallel encoders (turbo codes 2]) can be considered as a special case of woven turbo encoders, where only one outer and inner encoder is used. However, woven turbo codes with a larger number of outer codes yield higher minimum distances than turbo codes with random permutations.

Turbo codes are the most recent breakthrough in coding theory. However, the decoder’s implementation cost limits their incorporation in commercial systems. Although the decoding algorithm is highly data dominated, no true memory optimization study has been performed yet. We have extensively and systematically investigated different memory optimizations for the MAP (Maximum A Posteriori) class o...

3. Technologies for a new mobile broadcasting system 9 3.1 Full over-the-air (OTA) software upgradeability 9 3.2 Transmit diversity 10 3.3 Error correction coding 12 3.3.1 Turbo + RS coding 12 3.3.2 Turbo-Multi-level coded modulation (T-MLCM)+RS coding 13 3.3.3 Low Density Parity Check (LDPC) codes 13 3.4 Statistical multiplexing 14 3.5 Layered modulation & source coding 14 3.6 MPEG-4 Audio Ver...

introduction: the complex geometry of breast and also lung and heart inhomogeneities near the planning target volume (ptv) result in perturbations in dose distribution. this problem can result in overdosage or underdosage in the match region of the three treatment fields. the purpose of this study is to create a homogeneous dose distribution in the match region between the supraclavicular and t...

The rotordynamics and fluid dynamics of a turbo-machine considering the effect of fluid-solid interaction FSI are numerically investigated using finite element software ADINA. The iterative method is adopted in computation of coupled fields of displacement and fluid. What distinguishes the present study from previous ones is the use of ADINA’s rotational meshes and the FSI interface that separa...

An enhanced FEC system is proposed and described. The scheme has been simulated with both Single carrier and Multi-carrier (OFDM) Modulation. Purpose This proposal is offered as a basis for FEC in the 802.16.3 PHY layer. Notice This document has been prepared to assist IEEE 802.16. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). T...

The reliability of a data communication can be improved by using an automatic repeat request (ARQ) protocol, in which the receiver requests the retransmission of data packets when an error is detected in the received data. The hybrid ARQ (HARQ) scheme combines an ARQ and an error correction coding [1]. Turbo codes proposed by Berrou et al. in 1993 [2] show an error correction capability approac...