The effects of uniform spreading in OFDMCDMA systems is the harmonization at the reception of the Signal to Noise Ratio between the sub-bands which prevents the good performance of Successive Decoding algorithms. This paper proposes a new Hybrid Spread OFDM (SOFDM) transmission scheme in which the spreading of the information is adjustable and not uniform along the carrier (frequency selective)...

Since joint source-channel decoding is capable of exploiting the residual redundancy in the encoded source signals for improving the attainable error resilience, it has attracted substantial attention. Motivated by the principle of exploiting the source redundancy at the receiver, in this treatise we study the application of iterative Error Concealment (EC) for low-complexity uplink video commu...

In this paper, bandwidth ef£cient Type-I and Type-II hybridARQ (HARQ) schemes using turbo trellis coded modulation (TTCM) are proposed. These schemes combine the power ef£ciency of turbo codes with the bandwidth ef£ciency of trellis coded modulation (TCM) to create an effective hybrid FEC/ARQ system. Several packet combining schemes are presented for use in conjunction with iterative turbo deco...

Hamming code-based LDPC (H-LDPC) block codes are obtained by replacing the single parity-check constituent codes in Gallager’s LDPC codes with Hamming codes. This paper investigates the asymptotic performance of ensembles of random H-LDPC codes, used over the binary symmetric channel and decoded with a low-complexity hard-decision iterative decoding algorithm. It is shown that there exist H-LDP...

Iterative decoding of serially concatenated code is extended to punctured trellis-coded modulation. A system configuration, a decoding algorithm and a performance evaluation method are proposed. It realizes a total coding rate of m/(m+1) by puncturing parity bits. Simulation results indicate that the proposed system shows no flattening effect which is observed in parallel concatenated system an...

This letter proposes an efficient and simple stopping criterion for turbo decoding, which is derived by observing the behavior of log-likelihood ratio (LLR) values. Based on the behavior, the proposed criterion counts the number of absolute LLR values less than a threshold and the number of hard decision 1’s in order to complete the iterative decoding procedure. Simulation results show that the...

This paper considers the transmission of multiple descriptions over noisy channels rather than the on-oo channels that are traditionally considered. We introduce the use of iterative decoding techniques similar to those used in \turbo" decoding to decode multiple correlated descriptions transmitted over a noisy channel. For a given transmission rate per channel and a given channel state, the ee...

A novel bit-interleaved coded modulation with iterative detection and decoding (BICM-IDD) receiver for multiple-input and multipleoutput (MIMO) systems using Max-Log-MAP algorithm is proposed. This receiver improves the detection and decoding performance by an improved turbo principle, in which pre-scaling the input information of the detector is performed at each iteration. From an information...

The topic of interference cancellation in a coded Code Division Multiple Access (CDMA) system has been the focus of much recent research. Earlier works have studied methods for jointly decoding all the users resulting in most having an exponential complexity for the corresponding receiver. In this report, a number of di erent iterative decoding methods are proposed for the multi-user interferen...

Turbo codes were a major milestone in the forward error correction codes which can even achieve an excellent bit error rates at low SNR. The original proposal was for the BPSK scheme but were soon successful with multilevel coded as well. The “Turbo Trellis Coded Modulation” (TTCM) employing two TCM codes as parallel concatenation of two recursive TCM encoder, and adapted puncturing mechanism t...