An interference canceller comprises a composite interference vector (CIV) generator configured to produce a CIV by combining soft and/or hard estimates of interference, an interference-cancelling operator configured for generating a soft projection operator, and a soft-projection canceller configured for performing a soft projection of the received baseband signal to output an interference-cancelled signal. Weights used in the soft-projection operator are selected to maximize a post-processing SINR.

The present invention discloses a channel frequency spreading device for a CDMA system, including: an orthogonal sequence generating module, configured to generate orthogonal sequence sets; a storage module, connected to the orthogonal sequence generating module, and configured to store the orthogonal sequence sets; a control module, connected to the storage module, and configured to read available orthogonal sequences in the orthogonal sequence sets when receiving a user request control signal; and a channel machine, connected to the control module, and configured to receive user request data, and perform frequency spreading on the user request data according to the available orthogonal sequences and then output. The channel frequency spreading device for a CDMA system can improve the number of the sequences allocated by the cell, and solve the problem that the excessive users cannot communicate normally.

The present invention discloses a channel frequency spreading device for a CDMA system, including: an orthogonal sequence generating module, configured to generate orthogonal sequence sets; a storage module, connected to the orthogonal sequence generating module, and configured to store the orthogonal sequence sets; a control module, connected to the storage module, and configured to read available orthogonal sequences in the orthogonal sequence sets when receiving a user request control signal; and a channel machine, connected to the control module, and configured to receive user request data, and perform frequency spreading on the user request data according to the available orthogonal sequences and then output. The channel frequency spreading device for a CDMA system can improve the number of the sequences allocated by the cell, and solve the problem that the excessive users cannot communicate normally.

A wireless communication unit may receive a composite signal that includes data, a code division multiplexing (CDM) pilot sequence that is spread with a first channelization code, and a time division multiplexing (TDM) pilot sequence including a cyclic prefix. The TDM pilot sequence may be spread with a second channelization code. The composite signal may have a pre-defined portion of a time slot where the CDM pilot sequence is non-cyclic. The TDM pilot sequence may have a cyclic structure within the pre-defined portion of the time slot.

A wireless communication may receive a composite signal that includes data symbols, a code division multiplexing (CDM) pilot sequence that is spread with a first channelization code, and a time division multiplexing (TDM) pilot sequence including a cyclic prefix where the TDM pilot sequence is spread with a second channelization code. The composite signal may be received within a designated time region such that the CDM pilot sequence has non-cyclic properties over the designated time region. The composite signal may be descrambled with a non-cyclic scrambling code.

A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses at least one channel, includes the steps of: a) encoding the source data to generate at least one data part and a control part; b) generating at least one spreading code to be allocated to the channel, wherein each spreading code is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on same point or symmetrical with respect to a zero point on a phase domain; and c) spreading the control part and the data part by using the spreading code, to thereby generate the channel-modulated signal.

A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses at least one channel, includes the steps of: a) encoding the source data to generate at least one data part and a control part; b) generating at least one spreading code to be allocated to the channel, wherein each spreading code is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on same point or symmetrical with respect to a zero point on a phase domain; and c) spreading the control part and the data part by using the spreading code, to thereby generate the channel-modulated signal.

Aspects of the present disclosure provide techniques for variable spreading factor codes for non-orthogonal multiple access (NOMA). In an exemplary method, a base station assigns, from a first codebook of N short code sequences of length K, a subset of the short code sequences to a number of user equipments (UEs); receives a signal including uplink data or control signals from two or more of the UEs, wherein a first uplink data or control signal is sent using a first subsequence of one of the assigned short code sequences, and a second uplink data or control signal is sent using a second subsequence of one of the assigned short code sequences or using one of the assigned short code sequences; and decodes each uplink data or control signal in the signal based on the assigned short code sequences and subsequences of the assigned the short code sequences.

Aspects of the present disclosure provide techniques for variable spreading factor codes for non-orthogonal multiple access (NOMA). In an exemplary method, a base station assigns, from a first codebook of N short code sequences of length K, a subset of the short code sequences to a number of user equipments (UEs); receives a signal including uplink data or control signals from two or more of the UEs, wherein a first uplink data or control signal is sent using a first subsequence of one of the assigned short code sequences, and a second uplink data or control signal is sent using a second subsequence of one of the assigned short code sequences or using one of the assigned short code sequences; and decodes each uplink data or control signal in the signal based on the assigned short code sequences and subsequences of the assigned the short code sequences.

The present invention discloses a channel frequency spreading device for a CDMA system, including: an orthogonal sequence generating module, configured to generate orthogonal sequence sets; a storage module, connected to the orthogonal sequence generating module, and configured to store the orthogonal sequence sets; a control module, connected to the storage module, and configured to read available orthogonal sequences in the orthogonal sequence sets when receiving a user request control signal; and a channel machine, connected to the control module, and configured to receive user request data, and perform frequency spreading on the user request data according to the available orthogonal sequences and then output. The channel frequency spreading device for a CDMA system can improve the number of the sequences allocated by the cell, and solve the problem that the excessive users cannot communicate normally.