Multi-Carrier and Spread Spectrum Systems: From OFDM and MC ...

218 ApplicationsFirst, concrete examples of the application of OFDM/OFDMA for B3G cellular mobilesystems, i.e. LTE and WiMAX, are given. Then, future mobile radio concepts and fieldtrials based on OFDM and MC-CDMA are described. The OFDM-based IEEE 802.11astandard is studied thereafter. Finally, the DVB-T return channel (DVB-RCT) specificationwill be presented.5.2 3GPP Long Term Evolution (LTE)5.2.1 IntroductionThe Third Generation Partnership Project (3GPP) is the forum where WCDMA and itsevolutions, high speed packed access (HSPA) and 3GPP Long Term Evolution (LTE),have been specified. The standardization bodies ETSI, ARIB, TTC, TTA, CCSA, andATIS are the organizational partners of 3GPP. The evolution of 3G standards under 3GPPis illustrated in Figure 5-2 and briefly described in the following.WCDMAA cellular mobile radio is characterized by providing mobile services with high geographicalcoverage. The introduction of WCDMA in Europe, referred to as UMTS [3] (seeSection 1.3.3.2), was a move from mainly mobile voice communications towards mobilemultimedia applications. The first version of WCDMA is Release 99 (R99), which isoperated in the 3G carrier frequency bands at around 2 GHz using channels with 5 MHzbandwidth. Theoretical peak data rates of 2 Mbit/s are possible with R99 while in practice384 kbit/s are implemented.HSPAThe increasing demand for higher data rates resulted in the WCDMA evolutions highspeed downlink packet access (HSDPA) [1] and high speed uplink packet access (HSUPA)[2]. Both extensions are based on the R99 single-carrier WCDMA. They increase the datarate up to 14.4 Mbit/s with HSDPA (Release 5, R5) and 5.7 Mbit/s with HSUPA (Release6, R6) respectively. These improvements are obtained by introducing channel-dependentscheduling and hybrid ARQ (HARQ) with soft combining together with multiple codeallocation. The downlink additionally supports adaptive coding and modulation. The setof HSDPA and HSUPA is termed high speed packed access (HSPA).LTE3GPP LTE is also referred to as evolved universal terrestrial radio access (E-UTRA) orSuper 3G (S3G) and is introduced by 3GPP as Release 8 (R8) [8]. The specificationsdefine a new physical air interface in order to further increase the data rate of the cellularmobile radio compared to HSPA. The key differentiation compared to WCDMA andWCDMA (R99) HSPA (R5, R6) LTE (R8) 4GFigure 5-23G evolution within 3GPP