Multiuser detector for variable spreading factors

A method for assembling on a processor a response matrix with limited matrix bandwidth from a plurality of individual response matrices representing a plurality of filter response characteristics, comprising:

• (a) grouping the plurality of individual response matrices according to like spreading factors;
• (b) assembling spreading factor group matrices from said groups of individual response matrices with like spreading factors;
• and
• (c) forming a base total response matrix from a spreading factor group matrix having the lowest spreading factor.

A method of detecting in a received CDMA communication (r) a plurality of data communications each corresponding with a specific user (k) comprising:

• (a) acquiring impulse response estimates for symbols within each data communication;
• (b) constructing a system transmission response matrix for each of the user data communications (k) from said impulse response estimates;
• (c) assembling a well-banded total system transmission response matrix from all of said user system transmission response matrices;
• (d) filtering said received CDMA communication (r) with said total system transmission response matrix yielding a matched filter output;
• (e) forming an objective matrix based upon said total system transmission response matrix;
• (f) inverting said objective matrix;
• (g) multiplying said matched filter output with said inverted objective matrix yielding estimated user data;
• (h) descrambling said estimated user data yielding user data corresponding to the plurality of data communications;
• and
• (I) repeating steps (a)-(h) for a next CDMA communication.

A method of detecting in a received CDMA communication (r) a plurality of user (k) data communications (d(k)), each user data communication (d(k)) having same or different spreading factors (Q(k)), comprising:

• (a) acquiring impulse estimates corresponding with each symbol in each of the plurality of user data communications;
• (b) constructing a system transmission response matrix for each of the plurality of user data communications (d(k)) from said respective impulse response estimates;
• (c) assembling a well-banded total system transmission response matrix from all of said system transmission response matrices;
• (d) filtering the received CDMA communication (r) with said arranged total system transmission response matrix yielding estimated data outputs;
• (e) forming an objective matrix from said arranged total system response matrix;
• (f) inverting said objective matrix;
• (g) multiplying said estimated outputs with said inverted objective matrix yielding user data corresponding to the plurality of user data communications;
• and
• (h) repeating steps (a)-(g) for a next CDMA communication.

A multiuser detector that detects in a received CDMA communication (r) a plurality of user data communications (d(k)) comprising:

• means for acquiring impulse estimates corresponding with each symbol in each of the plurality of user data communications (d(k));
• means for assembling a system transmission response matrix for each of the plurality of user data communications (d(k)) from said respective impulse response estimates;
• means for assembling a total system transmission response matrix from all of said system transmission response matrices yielding a well-banded matrix;
• means for filtering the received CDMA communication with said total system transmission response matrix yielding estimated data outputs;
• means for forming an objective matrix from said arranged total system response matrix;
• means for inverting said objective matrix;
• and
• means for multiplying said estimated outputs with said inverted objective matrix yielding user data (d(k)) corresponding to the plurality of user data communications.