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

Radio Channel Characteristics 23– [EPA 5 Hz] Extended Pedestrian A with 5 Hz Doppler frequency– [EVA 5 Hz] Extended Vehicular A with 5 Hz Doppler frequency– [EVA 70 Hz] Extended Vehicular A with 70 Hz Doppler frequency– [ETU 70 Hz] Extended Typical Urban with 70 Hz Doppler frequency– [ETU 300 Hz] Extended Typical Urban with 300 Hz Doppler frequencyMulti-antenna channel models for LTE are defined by correlation matrices applied tothe channel models described in Table 1-3. MIMO channel models are defined for high,medium, and low correlations between antennas. The correlation matrix for the basestation with two antennas is( )1 αR BS =α ∗ . (1.16)1In the case of one antenna at the base station the correlation matrix R BS is equal to 1. Atthe mobile terminal station the correlation matrix is given by( )1 βR TS =β ∗ . (1.17)1The parameters α and β are defined in Table 1-5.For the 2 × 2 case the spatial channel correlation matrix R spat is defined asR spat = R BS ⊗ R TS =( ) ( )1 α 1 βα ∗ ⊗1 β ∗ =1⎛⎜⎝1 β α αββ ∗ 1 αβ ∗ αα ∗ α ∗ β 1 βα ∗ β ∗ α ∗ β ∗ 1⎞⎟⎠ . (1.18)where ⊗ is the Kronecker product. For the 1 × 2 case the spatial channel correlationmatrix R spat results in( ) 1 βR spat =β ∗ . (1.19)1Table 1-5 Correlation parameters for the LTE MIMOchannel models [1]Low correlation Medium correlation High correlationα β α β α β0 0 0.3 0.9 0.9 0.9WiMAX [16, 17, 31]IEEE 802.16x uses two categories of channel models, (i) one describing the fixed positionedTS channel with NLOS and (ii) the second one defining the behavior of themobile TS.