Narrowband PRACH with multiple tone hopping distances

摘要

Due to the limited dimensions of the NB that can be used by multiple users and in addition the possible large coverage area, timing offset estimation can be outside the NCP. The timing estimation inaccuracy may be improved by using more than one tone hopping distance for the PRACH. The device may then transmit a PRACH first tone and a second tone at a first hopping distance from the first tone. The apparatus may then transmit a PRACH third tone and a PRACH fourth tone at a second hopping distance from the third tone. The second hopping distance may be greater than the first hopping distance. The device may also transmit additional tones of PRACH using a random hopping distance. The receiving device may receive the transmitted PRACH and determine a phase estimate based on a set of tones having different hopping distances. [Selection] Figure 11