The uplink RB may include twelve sub-carriers in frequency domain. The uplink slot includes fourteen (for normal CP) or twelve (for extended CP) OFDM/DFT-S-OFDM symbols in time domain. A region defined by one sub-carrier in the frequency domain and one OFDM/DFT-S-OFDM symbol in the time domain is referred to as a RE and is uniquely identified by the index pair (k,l) in a slot, where k and l are indices in the frequency and time domains respectively. While uplink subframes in one component carrier (CC) are discussed herein, uplink subframes are defined for each CC.
FIG. 7 shows examples of several numerologies 901. The numerology #1 901a may be a basic numerology (e.g., a reference numerology). For example, a RE 995a of the basic numerology 901a may be defined with subcarrier spacing 905a of 15 kHz in frequency domain and 2048Ts+CP length (e.g., 160Ts or 144Ts) in time domain (i.e., symbol length #1 903a), where Ts denotes a baseband sampling time unit defined as 1/(15000*2048) seconds. For the i-th numerology, the subcarrier spacing 905 may be equal to 15*2i and the effective OFDM symbol length 2048*2?i*Ts. It may cause the symbol length is 2048*2?i*Ts+CP length (e.g., 160*2?i*Ts or 144*2?i*Ts). In other words, the subcarrier spacing of the i+1-th numerology is a double of the one for the i-th numerology, and the symbol length of the i+1-th numerology is a half of the one for the i-th numerology. FIG. 7 shows four numerologies, but the system may support another number of numerologies. Furthermore, the system does not have to support all of the 0-th to the I-th numerologies, i=0, 1, . . . , I.
