NPRACH FORMATS FOR NB-IOT TRANSMISSION IN TDD MODE Russian patent published in 2020 - IPC H04L5/00 

FIELD: communication equipment.

SUBSTANCE: invention relates to communication engineering and can be used in random access communication systems in TDD mode. Formats are defined so as to allow the use of legacy LTE subframe configurations for TDD. Formats specify a predetermined even number P of symbol groups constituting RA preamble, wherein each group of symbols comprises a cyclic prefix (CP) and a number X of symbols. P groups of symbols are divided into sets of groups of symbols built into 1, or 2, or 3 adjacent subframes of uplink, each of which contains at least two groups of symbols transmitted in series (i.e. continuously in time), and at least two sets of symbol groups are transmitted intermittently in time within the number of uplink subframes, on which preamble RA is transmitted. Number of groups of symbols in the set may be equal to two or three, and the number of groups of symbols is equal to four or six, respectively. Groups of symbols in the set are transmitted in adjacent subframes of the uplink. Five format variants which correspond to different TDD LTE configurations are determined.

EFFECT: technical result consists in improvement of throughput capacity of transmission due to use of formats of random access (RA), which are determined for operation NB-IoT in mode TDD.

16 cl, 12 dwg, 12 tbl