Feng-Wen Sun

DVB-S2 low density parity check codes with near Shannon limit performance

Low density parity check (LDPC) codes are chosen for the second generation digital video broadcasting (DVB) standard. In this paper, we review LDPC codes in general, present belief propagation decoding algorithm in simple terms, describe the standardized LDPC codes and show their performance. Copyright

An innovative low-density parity-check code design with near-Shannon-limit performance and simple implementation

A novel parity-check matrix design for low-density parity-check (LDPC) codes is described. By eliminating the routing problem associated with LDPC codes, the design results in a small implementation area, and the codes have outstanding error-rate performance close to the Shannon limit for a wide range of code rates, from 1/4 to 9/10, and for various modulation schemes such as binary phase-shift keying (PSK), quaternary PSK, 8-PSK, 16-amplitude PSK (APSK), and 32-APSK. As a result, LDPC codes designed with this method have been standardized for next-generation digital video broadcasting.

Impact of near Shannon-limit codes on wireless communications technology

Tremendous progress has been made on channel coding techniques during the last decade, starting from the invention of turbo codes and the rediscovery of the low-density parity check (LDPC) codes. These codes essentially closed the gap between the Shannon capacity limit and practical implementation. Commercial adoption of these new coding techniques, however, depends heavily on the introduction of the technology into communication standards. In this paper, we briefly review the considerations when turbo codes and LDPC codes were introduced to the 3/sup rd/ generation wireless standards (3GPP and 3GPP2), and the digital video broadcast for satellite standard (DVB-S2), respectively. We then examine a few possible approaches to take advantage of these powerful codes for future wireless channels.

Third Generation Wireless Communication Technologies

The debate on the third generation wireless system is not about the selection of the core technologies, such as CDMA versus TDMA. Rather, it is on whether the design objectives properly address the market needs and whether there are sufficient technical innovations to achieve these objectives. This chapter discusses the essential design objectives for a successful third generation wireless system. A number of key innovations intended to meet these objectives are presented. We will briefly describe the cdma2000 forward and reverse link design. In the forward link an alternative approach for the 3X mode that exhibits advantages of two approaches currently included in the cdma2000 standard is outlined. In the reverse link, we will present a media access scheme that combines PRMA for large packets and ISMA with capture message for short packets to significantly improve the efficiency of channel utilisation for high-speed data transmission. In both the forward and reverse links, Turbo FEC codes further increase the underlying channel capacity by 50–60 percent. By combining an efficient reverse link multiple access architecture, and optimised FEC coding techniques, third generation wireless systems can reach an unprecedented level of performance in high-speed packet data delivery and improved voice capacity with minimum impact on implementation complexity.

Wireless communications technology and network architecture for the new millennium

Wireless data applications have just begun to gain popularity in the marketplace. The rollout of 3rd generation (3G) wireless networks is anticipated in the next few years. We examine wireless data networks that are complementary to the 3G wireless networks, their technologies and the challenges. In particular, we present some of the industry initiatives in the millimeter wave frequency bands for broadband and satellite delivered fixed wireless data network. Furthermore, we offer our perspectives on how these different networks will evolve and inter-work together to provide a seamless experience for the end users. Fixed data networks need to be competitive with wire-line services, this requires us to push advanced signal processing technologies further. We present the latest advances that we have made in channel coding and signal processing technologies to approach that goal.

Applying Near Shannon-limit Codes to Wireless Communications

Tremendous progress has been made on channel coding techniques during the last decade, starting from the invention of turbo codes and the rediscovery of the low-density parity check (LDPC) codes. These codes essentially closed the gap between the Shannon capacity limit and practical implementation. Commercial adoption of these new coding techniques, however, depends heavily on the introduction of the technology into communication standards. In this paper, we will briefly review the considerations when turbo codes and LDPC codes were introduced to the 3rd generation wireless standards (3GPP& 3GPP2), and the digital video broadcast for satellite standard (DVB-S2), respectively. We will then examine a few possible approaches to take advantage of these powerful codes for future wireless channels.