tunately, with VoIP traffic the data amount for one user typically requires at most 2 PRBs, and therefore it is difficult to achieve efficient frequency diversity with localized transmission. Frequency diversity offered by method (1) can be further improved if HARQ retransmissions are scheduled in different loca- tions in frequency than previous transmission(s). VoIP LTE DL performance of semi-persistent PS with wideband CQI was ana- lyzed in [34] by comparing localized transmission with method (1) (with HARQ retransmissions scheduled SO that frequency diversity is maximized) and distributed transmission with Nd = 2. It was shown that distributed transmission provided only 2% higher capacity than localized transmission with the enhanced method (1). In Table 10.3 relative losses in capacity due to utilization of wideband CQI instead of narrowband CQI are given for fully dynamic and semi-persistent PS methods. Here it is assumed that localized transmission with method (1), assum- ing diversity enhancement over HARQ retransmissions, is used. As can be seen from the results, when the frequency domain scheduling losses are compensated with efficient utilization of frequency diversity, degradation in performance due to usage of wideband CQI stays tolerable. Without frequency diversity enhancements, corresponding losses would be higher. Moreover, the relative losses in performance realized by the semi-persistent PS are only half of the corresponding losses for fully dynamic PS, as only HARQ retransmissions and SID transmissions benefit from FD scheduling gains. 10.6.2.4 Adaptive HARQ in UL For trade-off purposes, the currently agreed-on proposal in 3GPP is to use a syn- chronous nonadaptive HARQ protocol as much as possible for LTE UL. It means adaptive HARQ will be enabled for use if fully nonadaptive HARQ is impossible to be used. Such a decision is due to the drawbacks of fully nonadaptive HARQ. The nature of the nonadaptive solution is that retransmissions occur at a predefined (normally fixed) time after the previo