ce (AVI). Furthermore, for LTE the Spatial Channel Model [38] SCM-C shall be employed. The main simulation parameters are based on [17] and are also listed in Table 10.6. UEs are uniformly distributed in 3 center cells and assigned with VoIP traffic. The VoIP traffic is modeled as in [11] and the most important characteristics are summarized in Table 10.7. Moreover, Table 10.7 Main Traffic Related Assumptions Description Settings Codec AMR 12.2 kb/s, AMR 7.95 kb/s Header compression Payload including all overhead 40 bytes for AMR 12.2 kbps, 28 bytes for AMR 7.95 kbps SID payload including all overhead 15 bytes Voice activity Talk spurt Negative exponential distribution, mean 2.0 S One-way delay (ms) © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology Table 10.8 Main DL Related Simulation Parameters Description Settings Multiple access OFDMA eNode-B Tx power 43 dBm (5 MHz) Max C/l limit in the receiver 22 dB Transmission scheme 2 X 2 Space-Time Transmit Diversity (STTD) Receivers 2-antenna with MRC combining CQI settings Zero mean i.i.d. Gaussian error with 1 dB std, 5-ms measurement window, 2ms reporting delay DL L1/L2 control channel 4 OFDM symbols per TTI including pilot overhead overhead MCS set As in [17] 8 HARQ SAW channels. Asynchronous, adaptive HARQ with chase combining. Maximum 6 retransmissions Packet scheduler VolP optimized PS, semi-persistent PS Packet bundling Can be used for fully dynamic PS (up to 2 packets could be bundled per TTI) PDCCH assumption 10 CCEs reserved for DL traffic scheduling per TTI (max 10 users could be scheduled dynamically per TTI) the main DL related parameters and UL related parameters are summarized in Table 10.8 and Table 10.9, respectively. The performance is evaluated in terms of VoIP capacity. VoIP capacity is defined according to the quality criteria given in Section 10.3.3; that is, capacity is given as the maximum number of users that can be supported without exceeding 5% outage. The user is in outage if more than 2% of t