US Patent No. 10,433,335


Patent No. 10,433,335
Issue Date October 01, 2019
Title System And Method For Beam-based Physical Random-access
Inventorship Mattias Frenne, Uppsala (SE)
Johan Furuskog, Stockholm (SE)
Stefan Parkvall, Bromma (SE)
Assignee Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)

Claim of US Patent No. 10,433,335

1. A method in a wireless device for performing random access to a network node, the method comprising:receiving a set of downlink beam-specific reference signals (BRSs) from the network node, each downlink BRS being unique per beam and known from standard specification;
determining a preferred downlink beam-specific reference signal (BRS) from the set of downlink BRSs based on a received signal power for each downlink BRS in the set of downlink BRSs;
selecting, based on the preferred downlink BRS, a random-access resource to be used for transmitting a random-access attempt to the network node, the random-access resource selected according to one or more pre-defined association rules defining, for each downlink BRS in the set of downlink BRSs, an association between a random-access resource and the each downlink BRS; and
transmitting a random-access attempt on a Random Access Channel (RACH) to the network node using the selected random-access resource; and
receiving a random-access response message on RACH in a downlink beam that is preferred by the wireless device and that is indicated by the selected random-access resource.