Communication apparatus, communication system, communication method, and computer-readable storage medium

A communication apparatus comprising:

• one or more memory devices configured to store information indicating a first base set including a first base sequence to an N-th base sequence (N being an integer of 2 or more) which are sequences of L number of complex numbers (L being an integer of 2 or more), and timing information indicating reception timings of sequences;
• and
• one or more processors configured to:
• receive a first reception sequence to an N-th reception sequence according to the timing information;
• and
• determine reception data, based on a total value obtained by obtaining a periodic correlation between an n-th reception sequence (n being an integer from 1 to N) and an n-th base sequence, and totaling correlation values with same shift amount of the obtained periodic correlation for the first reception sequence to the N-th reception sequence, wherein
• the first base sequence to the N-th base sequence satisfy a first condition of:
• a total across the first base sequence to the N-th base sequence of correlation values of autocorrelation is not 0 when a shift amount is 0, and
• a total across the first base sequence to the N-th base sequence of correlation values of autocorrelation is 0 when a shift amount is different from 0 used in data reception.

A communication method for a communication apparatus comprising:

• determining a shift amount based on transmission data;
• generating a first shift sequence to an N-th shift sequence by cyclic shifting a first base sequence to an N-th base sequence (N being an integer of 2 or more) which are sequences of an L number (L being an integer of 2 or more) of complex numbers by the shift amount;
• and
• transmitting the first shift sequence to the N-th shift sequence according to timing information indicating transmission timings of sequences, wherein
• the first base sequence to the N-th base sequence satisfy a first condition of:
• a total across the first base sequence to the N-th base sequence of correlation values of autocorrelation is not 0 when a shift amount is 0, and
• a total across the first base sequence to the N-th base sequence of correlation values of autocorrelation is 0 when a shift amount is different from 0 used in data transmission.

A communication method for a communication apparatus comprising:

• receiving a first reception sequence to an N-th reception sequence corresponding to a first base sequence to an N-th base sequence (N being an integer of 2 or more) which are sequences of L number (L being an integer of 2 or more) complex numbers according to timing information indicating reception timings of the first reception sequence to the N-th reception sequence;
• and
• determining reception data based on a total value obtained by obtaining a periodic correlation between an n-th reception sequence (n being an integer from 1 to N) and an n-th base sequence and totaling correlation values with same shift amount of the obtained periodic correlation for the first reception sequence to the N-th reception sequence, wherein
• the first base sequence to the N-th base sequence satisfy a first condition of:
• a total across the first base sequence to the N-th base sequence of correlation values of autocorrelation is not 0 when a shift amount is 0, and
• a total across the first base sequence to the N-th base sequence of correlation values of autocorrelation is 0 when a shift amount is different from 0 used in data reception.

A communication system comprising:

• an access point;
• and
• at least two communication apparatuses, wherein
• each of the at least two communication apparatuses include:
• one or more memory devices configured to store information indicating a base set including a first base sequence to an N-th base sequence (N being an integer of 2 or more) which are sequences of L number (L being an integer of 2 or more) of complex numbers, and timing information indicating transmission timings of sequences,
• one or more processors configured to:
• generate a first shift sequence to an N-th shift sequence by determining a shift amount based on data transmitted to the access point, cyclic shifting an n-th base sequence (n being an integer from 1 to N) by the shift amount, and generating an n-th shift sequence, and
• transmit the first shift sequence to the N-th shift sequence according to the timing information, wherein
• the first base sequence to the N-th base sequence satisfy a first condition of:
• a total across the first base sequence to the N-th base sequence of correlation values of autocorrelation is not 0 when a shift amount is 0, and
• a total across the first base sequence to the N-th base sequence of correlation values of autocorrelation is 0 when a shift amount is different from 0 used in transmission,
• a first communication apparatus among the at least two communication apparatuses stores a first base set as the base set and holds first timing information as the timing information,
• a second communication apparatus among the at least two communication apparatuses stores a second base set as the base set and holds second timing information as the timing information,
• the first base set and the second base set satisfy a second condition of:
• a total of correlation values with same shift amount across the first base sequence to the N-th base sequence of periodic correlation between the n-th base sequence of the first base set and the n-th base sequence of the second base set is 0 for all shift amounts used in data transmission, and
• the transmission timings of the first shift sequence to the N-th shift sequence indicated by the first timing information are same as the transmission timings of the first shift sequence to the N-th shift sequence indicated by the second timing information.