Frame structure type 1 is applicable to both full duplex and half duplex FDD. Each radio frame is T=307200-T = 10 ms long and consists of 20 slots of length 7t=15360-T, = 0.5 ms, numbered from 0 to 19. A subframe is defined as two consecutive slots where subframe i consists of slots 2i and 2i+1. For FDD, 10 subframes are available for downlink transmission and 10 subframes are available for uplink transmissions in each 10 ms interval. Uplink and downlink transmissions are separated in the frequency domain. In half-duplex FDD operation, the UE cannot transmit and receive at the same time while there are no such restrictions in full-duplex FDD. One slot, Ta 153607,-0.5 ms #0 #1 One radio frame, T=3072007,- 10 ms One subframe #12 #3 # 18 Figure 4.1-1: Frame structure type 1. # 19 The following information on resource blocks in the downlink is also taken from the LTE standard 6.2.3 Resource blocks Resource blocks are used to describe the mapping of certain physical channels to resource elements. Physical and virtual resource blocks are defined. A physical resource block is defined as Nmb consecutive OFDM symbols in the time domain and N consecutive symb subcarriers in the frequency domain, where Nomb and N are given by Table 6.2.3-1. A physical resource block thus symb consists of ND XNRB resource elements, corresponding to one slot in the time domain and 180 kHz in the frequency domain. The LTE standard includes the following figure showing the downlink resource grid for normal cyclic prefix: NRB XNRB Subcarrier NRB S Subcarrier One downlink slot Tlot 1=0 NDL symb OFDM symbols k=NO NB-1 RB Resource block N symb XNRB resource elements SC k=0 Resource element 1 = NDL symb-1 Figure 6.2.2-1: Downlink resource grid. (k.1) 1) Answer the following questions: i. What is the spacing between subcarriers in LTE? ii. What is the duration of a resource element in LTE? What is the bandwidth a resource block in LTE? iii. iv. What is the duration of a resource block V. What is the meaning of T, and what is its numerical value? 2) Design an LTE system that transmits 100a Mbits over an allocated channel bandwidth of b MHz. Assume 16QAM modulation scheme. i. ii. iii. iv. V. In view of the given bandwidth, how many subcarriers does the OFDM symbol have? Choose a value that is a power of 2. How many symbols and how many bits does each OFDM symbol carry? How many bits per subframe? How many bits per frame? How many frames?