Multi-user code division multiple access communication method, and corresponding transmitter and receiver

A multi-user code division multiple access communication method, applied to a receiver, comprising:

• the receiver receiving signals transmitted by a plurality of transmitters, wherein, the signals transmitted by the plurality of transmitters are generated by the plurality of transmitters using respective complex-valued spreading sequences respectively to perform spreading processing on respective data symbols to be sent and then respectively modulating generated spread symbol sequences onto the same time-frequency resources;
• the receiver performing reception detection on the received signals transmitted by the plurality of transmitters by using an interference cancellation signal detector, wherein the complex-valued spreading sequences used by the plurality of transmitters are used during detection;
• wherein, each element of the complex-valued spreading sequences is a complex number and values of real and imaginary parts of all elements in the complex-valued spreading sequences are from an M-element set of real numbers, wherein, M is an integer larger than or equal to 2;
• wherein:
• the M is an odd number and the M-element set of real numbers is a set of M integers ranging from [−(M−1)/2, (M−1)/2];
• or
• the M is an even number and the M-element set of real numbers is a set of M odd numbers ranging from [−(M−1), (M−1)];
• or
• the M is an odd number and the M-element set of real numbers is a set of M real numbers obtained by respectively multiplying M integers ranging from [−(M−1)/2, (M−1)/2] by a corresponding normalization coefficient;
• or
• the M is an even number and the M-element set of real numbers is a set of M real numbers obtained by respectively multiplying M odd numbers ranging from [−(M−1), (M−1)] by a corresponding normalization coefficient.

A transmitter in a multi-user code division multiple access communication system, comprising hardware performing instructions stored in a non-transitory computer readable medium which executes steps in following units:

• a sequence determining unit configured to determine a complex-valued spreading sequence to be used, wherein, each element of the complex-valued spreading sequence is a complex number, and values of real and imaginary parts of all elements in the complex-valued spreading sequence are from an M-element set of real numbers, wherein, M is an integer larger than or equal to 2;
• a spreading unit configured to perform spreading processing on data symbols to be sent by using the complex-valued spreading sequence to generate a spread symbol sequence;
• and
• a signal sending unit configured to send the spread symbol sequence;
• wherein:
• the values of real and imaginary parts of all elements in the complex-valued spreading sequence determined by the sequence determining unit are from an M-element set of real numbers, wherein:
• the M is an odd number and the M-element set of real numbers is a set of M integers ranging from [−(M−1)/2, (M−1)/2];
• or
• the M is an even number and the M-element set of real numbers is a set of M odd numbers ranging from [−(M−1), (M−1)];
• or
• the M is an odd number and the M-element set of real numbers is a set of M real numbers obtained by respectively multiplying M integers ranging from [−(M−1)/2, (M−1)/2] by a corresponding normalization coefficient;
• or
• the M is an even number and the M-element set of real numbers is a set of M real numbers obtained by respectively multiplying M odd numbers ranging from [−(M−1), (M−1)] by a corresponding normalization coefficient.

A receiver in a multi-user code division multiple access communication system, comprising hardware performing instructions stored in a non-transitory computer readable medium which executes steps in following units:

• a signal receiving unit configured to receive signals transmitted by a plurality of transmitters, wherein the signals transmitted by the plurality of transmitters are generated by the plurality of transmitters using respective complex-valued spreading sequences respectively to perform spreading processing on respective data symbols to be sent and then respectively modulating generated spread symbol sequences onto the same time-frequency resources;
• a reception detecting unit configured to perform reception detection on the received signals transmitted by the plurality of transmitters by using an interference cancellation signal detector, wherein the complex-valued spreading sequences used by the plurality of transmitters are used during detection;
• wherein, each element of the complex-valued spreading sequences is a complex number and values of real and imaginary parts of all elements in the complex-valued spreading sequences are from an M-element set of real numbers, wherein, M is an integer larger than or equal to 2;
• wherein:
• in the complex-valued spreading sequences, used by the plurality of transmitters, which are used during detection by the reception detecting unit, the values of real and imaginary parts of all elements are from an M-element set of real numbers, wherein:
• the M is an odd number and the M-element set of real numbers is a set of M integers ranging from [−(M−1)/2, (M−1)/2];
• or
• the M is an even number and the M-element set of real numbers is a set of M odd numbers ranging from [−(M−1), (M−1)];
• or
• the M is an odd number and the M-element set of real numbers is a set of M real numbers obtained by respectively multiplying M integers ranging from [−(M−1)/2, (M−1)/2] by a corresponding normalization coefficient;
• or
• the M is an even number and the M-element set of real numbers is a set of M real numbers obtained by respectively multiplying M odd numbers ranging from [−(M−1), (M−1)] by a corresponding normalization coefficient.