DMRS transmission

A method implemented at a base station, the method comprising:

• generating, based on a first sequence, a Demodulation Reference Signal (DMRS) sequence for an uplink channel, wherein the first sequence is obtained as complex-valued modulation symbols resulting from a π/2-Binary Phase Shift Keying (BPSK) modulation applied to a binary sequence given by a table comprising a plurality of sequences;
• and
• receiving, over the uplink channel, the DMRS sequence from a terminal device, wherein,
• in a case where a length of the first sequence is 12, the plurality of sequences include the following:
• {0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0} and
• {0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0},
• in a case where a length of the first sequence is 18, the plurality of sequences include the following:
• {1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0} and
• {1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0}, and
• in a case where a length of the first sequence is 24, the plurality of first sequences include the following:
• {1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0},
• {1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0}, and
• {0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0}.

A terminal device comprising:

• a controller configured to generate, based on a first sequence, a Demodulation Reference Signal (DMRS) sequence for an uplink channel, wherein the first sequence is obtained as complex-valued modulation symbols resulting from a π/2-Binary Phase Shift Keying (BPSK) modulation applied to a binary sequence given by a table comprising a plurality of sequences;
• and
• a transmitter configured to transmit, over the uplink channel, the DMRS sequence to a base station, wherein,
• in a case where a length of the first sequence is 12, the plurality of first sequences include the following:
• {0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0} and
• {0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0},
• in a case where a length of the first sequence is 18, the plurality of first sequences include the following:
• {1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0} and
• {1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0}, and
• in a case where a length of the first sequence is 24, the plurality of first sequences include the following:
• {1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0},
• {1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0}, and
• {0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0}.