차세대 DVB-RCS 시스템을 위한 효율적인 채널 부호화 알고리즘 연구

Abstract

The improving the performance of the return link of interactive satellite terminals is an important objective given the target to lower the cost of the terminals/the satellite bandwidth. A flexible error-correcting turbo code has been devised within the ESA TRP (Technology Research Program) activity.

This code (nicknamed Turbo Φ code) is derived from the extension of the DVB-RCS Turbo code to 16 states. This code is intended to offer near-Shannon performance on Gaussian channel, in most situations of block size, coding rate up to 8/9 and associated modulation. However, some paper described Turbo Φ codes with linear modulation are not suitable for non-linear satellite channel.

Therefore, soft-decision decoding of algebraic code such as BCH code with CPM (Continuous Phase Modulation) has been an area of active research interest in non-linear power amplifiers, such as satellite channels recently. The expert group recommends extended BCH (e-BCH) code with CPM is employed in DVB-RCS standard.

However, the performance of soft-decision decoding for e-BCH code is not much improved for iterations. This means that iterations are not impact on the performance.

So, there has been intensive focus on TPC (Turbo Product Codes) which has low latency and simple structures compare with turbo code. It achieves near-optimum performance at low signal-to-noise ratio. TPC are two dimensional code constructed from small component codes. This paper proposed optimal structure of Turbo Φ codes and combined e-BCH code with rate-compatible TPC which makes various coding rates by zero padding the row and/or column to adapt Next Generation (NG) DVB-RCS system.