Innovative Space-Time-Space Block Code for Next Generation Handheld Systems

Abstract

Broadcasting digital TV is currently an area of intensive development and standardisation activities. Actually, different groups are working on the standardisation problem. In Europe, the digital video broadcasting (DVB) consortium has adopted different standards for terrestrial (DVB-T) fixed reception, handheld (DVB-H) reception, satellite (DVB-S) reception as well as an hybrid reception like DVB-SH. In June 2008, the DVB-T2 was born extracting a lot of specifications from DVB-S2 and proposing some specifications for an eventual use of handheld reception. Now, we are working towards a second generation of DVB-SH called next generation handheld (NGH). Technically, DVB-SH system provides an efficient and flexible mean of carrying broadcast services over an hybrid satellite and terrestrial infrastructure operating at frequencies below 3 GHz to a variety of portable, mobile and fixed terminals. Target terminals include handheld, vehicle-mounted, nomadic (e.g. laptops) and stationary terminals. The broadcast services encompass streaming services such as television, radio programs as well as download services enabling for example personal video recorder services. Typically, Lbands (1-2 GHz) and S-bands (2-4 GHz) are used for land mobile satellite (LMS) services. The DVB-SH system coverage is obtained by combining a satellite component (SATC) and, where necessary, a terrestrial component (TC) to ensure service continuity in areas where the satellite alone cannot provide the required quality of service (QoS). The SATC ensures wide area coverage while the TC provides cellular-type coverage. In the DVB-SH standard, two main physical layer configurations are supported. SH-A allows (but does not impose) a single frequency network (SFN) (Mattson, 2005) between the SATC and the TC, using the orthogonal frequency division multiplexing (OFDM) technique. SH-B supports a time division multiplexing (TDM) for the SATC and the OFDM technique for the TC. The SFN presents great advantages by transmitting lower power at various sites throughout the coverage area. In an SFN, the different antennas transmit the same signal at the same moment on the same carrier frequency. The multi frequency network (MFN) allows however an optimization of the waveform and of the forward error correction (FEC) parameters according to the transmission environment. The existing SFN architectures are achieved in a single input single output system (SISO) since their deployment is very simple due to the use of one transmitting antenna by site. However, due to the increase of client services demand, it is desirable to deploy SFN with new multiple input multiple output (MIMO) techniques which ensure high spectrum efficiency as well as high diversity gain. In