CDMA Rake reception signal combining

Claim 2

A method according to claim 1, wherein the step of obtaining the correlation values comprises the step of obtaining a plurality of correlation values by de-spreading the reception signal by using the preset reference reception delay amounts.

Claim 3

A method according to claim 1, wherein the step of obtaining the correlation values comprises the steps of: obtaining a plurality of correlation values by separately de-spreading the reception signal by using the preset reference reception delay amounts and corrected reception delay amounts obtained by slightly correcting the reference reception delay amounts; and selecting one of an optimal correlation value from the obtained correlation values.

Claim 4

A method according to claim 3, wherein the step of de-spreading comprises the step of separately de-spreading the reception signal by using the preset reference reception delay amounts and a plurality of corrected reception delay amounts obtained by increasing/decreasing the reference reception delay amounts by a predetermined correction amount.

Claim 5

A method according to claim 3 or 4, further comprising the steps of: comparing reception delay amounts corresponding to selected optimal correlation values; and when correlation values using the same reception delay amount are selected, synthesizing only detection signals corresponding to one of the correlation values.

Claim 6

A method according to claim 3,4 or 5, wherein the step of selecting an optimal correlation value comprises the steps of: measuring an interference wave level from each obtained correlation value; calculating an SIR based on each measured interference wave level and a corresponding correlation value; and selecting a correlation value, of the calculated SIRs, from which an optimal reception quality is obtained as an optimal correlation value.

Claim 8

A CDMA receiver comprising: a synchronous acquisition following section (105) in which a plurality of reference reception delay amounts are preset on the basis of a correlation profile obtained by de-spreading a reception signal; a plurality of reception processing sections (102A - 102N) for outputting detection signals on the basis of the respective correlation values obtained by de-spreading the reception signal by using the respective reference reception delay amounts set in said synchronous acquisition following section; a synthesizing section (103) for synthesizing the respective detection signals from said reception processing sections; and a decoding section (104) for decoding a synthetic output from said synthesizing section, characterized in that each of said reception processing sections comprises correlation calculation means (181 - 185) for obtaining a correlation value on the basis of the reference reception delay amount designated by said synchronous acquisition following section; interference wave level measuring means (116) for measuring an interference wave level on the basis of the correlation value from said correlation value calculation means, SIR calculation means for calculating a reception quality (SIR) on the basis of the interference wave level from said interference wave level measuring means and a corresponding correlation value, and determination means (110) for determining, on the basis of the SIR from said SIR calculation means, whether detection signals obtained from corresponding correlation values are synthesized.

Claim 9

A receiver according to claim 8, wherein said correlation value calculation means obtains a correlation value by de-spreading the reception signal by using a reference reception delay amount designated by said synchronous acquisition following section.

Claim 10

A receiver according to claim 8, wherein said correlation value calculation means comprises: a plurality of correlators (181 - 185) for obtaining correlation values by de-spreading the reception signal by using a reference reception delay amount designated by said synchronous acquisition following section and a corrected reception delay amount obtained by slightly correcting the reference reception delay amount; and optimal correlation value selection means (110, 111, 191 - 193) for selecting an optimal correlation value from the respective correlation values from said correlators.

Claim 11

A receiver according to claim 10, wherein said plurality of correlators separately de-spread the reception signal by using a reference reception delay amount and a plurality of corrected reception delay amounts obtained by increasing/decreasing the reference reception delay amount by a predetermined correction amount.

Claim 12

A receiver according to claim 10 or 11, further comprising: delay amount comparing means (117) for comparing reception delay amounts corresponding to selected optimal correlation values; and path selection means (120) for, when a comparison result obtained by said delay amount comparing means indicates that correlation values using the same reception delay amount are selected, outputting only a detection signal corresponding to one of the correlation values.

Claim 13

A receiver according to claim 10, 11 or 12, wherein said optimal correlation value selection means comprises: a plurality of SIR calculating sections (191 - 193) for separately calculating SIRs on the basis of interference wave levels from said interference wave level measuring means and corresponding correlation values; and a correlation value selecting section (110, 111) for selecting a correlation value from which an optimal SIR of the calculated SIRs is obtained as an optimal correlation value.

Claim 14

A receiver according to anyone of claims 8 to 13, further comprising: an SIR calculating section (191 - 193) for calculating an SIR corresponding to a correlation value on the basis of a correlation value from said optimal correlation value calculating means and an interference wave level obtained from a corresponding correlation value; and determination section (210) for determining, on the basis of the reception quality from the SIR, whether detection signals obtained from corresponding correlation values are synthesized.