Mobility Aspects of Physical Layer in Future Generation Wireless Networks

The demand from social market for high speed broadband communications over wireless media is pushing the requirements of both the mobile and fixed networks. The past decade has witnessed tremendous advancement in the blooming development of mobile communications including mobile-to-mobile and mobile-to-fixed networks. Wireless fixed and cellular networks of future generation will need to support new protocols, standards and architecture leading to all IP-based networks. Different systems like digital video broadcasting (DVB) via satellites have great success commercially as they provide ubiquitous coverage and serve large number of users with high signal quality. Satellite communications have proven to be attractive means to provide communication services such as broadband communications (3G services), surveillance, remote monitoring, intelligent transportation systems, navigation, traffic warnings and location-based information etc. to fixed and mobile users. However, to meet the growing demands of mass market integration of satellites and terrestrial networks seems to be inevitable for future generation wireless networks. Due to technology advances and growing traffic demands, communication systems must evolve to completely new systems or within themselves in order to provide broadband services in a safe and efficient way. While enhancements continue to be made to leverage the maximum performance from currently deployed systems, there is a bound to the level to which further improvements will be effective. If the only purpose were to deliver superior performance, then this in itself would be relatively easy to accomplish. The added complexity is that such superior performance must be delivered through systems which are cheaper from installation and maintenance prospect. Users have experienced an incredible reduction in telecommunications charges and they now anticipate receiving higher quality communication services at low cost. Therefore, in deciding the subsequent standardization step, there must be a dual approach: in search of substantial performance enhancement but at reduced cost. Long Term Evolution (LTE) is that next step and will be the basis on which future mobile telecommunications systems will be built. LTE is the first cellular communication system optimized from the outset to support packet-switched data services, within which packetized voice communications are just one part. In case of highly mobile scenarios, the effects of signal blockages and Doppler shifts introduce more burdens on the receiver demodulator. The signals blockage is prominent in the case of land mobile communications as compared to satellite communications. In deciding the technologies to comprise in LTE, one of the key concerns is the trade-off