Interference signal canceling apparatus and interference signal canceling method
View Patent ↗An interference cancellation apparatus and method may remove interference from a directional array combined signal that is received by an array antenna and array combined on a directivity-by-directivity basis. The apparatus and method input a plurality of array combined signals subjected to array combining on a directivity-by-directivity basis to select an array-combined signal corresponding to a path. A correlation value is detected between the selected array combined signal and a spread code. Detected correlation values are combined to generate a combined value, and the combined value is used to generate a temporarily determined value. The temporarily determined value is re-spread to generate a re-spread signal, and re-spread signals are sorted for every directivity, on a per path basis. The re-spread signals sorted for every directivity are then added to generate a replica signal.
1. A multistage interference signal canceling apparatus that cancels interference from a directional array combined signal that is received by an array antenna and array combined on a directivity-by-directivity basis, said apparatus comprising:
an interference canceling unit for generating, at every stage, a replica signal of a user;
delay means for delaying, at a stage other than a final stage, a received signal by a processing time of the interference canceling unit;
canceling means for removing replica signals of all users from the received signal of each directivity, and obtaining a residual signal of the user;
adding means for adding the replica signal and the residual signal on a per user basis, and outputting the result to an interference canceling unit of a next stage,
wherein the interference canceling unit comprises:
directivity selecting means for selecting the directional array combined signal on a per path basis; <despreading means for detecting a correlation value between the selected directional array combined signal and a spreading code,
combining means for combining detected correlation values to generate a combined value;
temporary determining means for temporarily determining the combined value to generate a temporarily determined value;
re-spreading means for re-spreading the temporarily determined value to generate a re-spread signal;
dividing means for sorting re-spread signals for every directivity, on a per path basis; and
adding means for adding the re-spread signals sorted for every directivity to generate a replica signal.
2. The interference signal canceling apparatus according to claim 1 , wherein said canceling means cancels replica signals of other users from the directional array combined signal.
3. A base station apparatus having an array antenna and an multistage interference signal canceling apparatus that cancels interference from a directional array combined signal that is received by an array antenna and array combined on a directivity-by-directivity basis, said multistage interference signal canceling apparatus comprising:
an interference canceling unit for generating, at every stage, a replica signal of a user;
delay means for delaying, at a stage other than a final stage, a received signal by a processing time of the interference canceling unit;
canceling means for removing replica signals of all users from the received signal of each directivity, and obtaining a residual signal of the user;
adding means for adding the replica signal and the residual signal on a per user basis, and outputting the result to an interference canceling unit of a next stage,
wherein the interference canceling unit comprises:
directivity selecting means for selecting the directional array combined signal on a per path basis;
despreading means for detecting a correlation value between the selected directional array combined signal and a spreading code,
combining means for combining detected correlation values to generate a combined value;
temporary determining means for temporarily determining the combined value to generate a temporarily determined value;
re-spreading means for re-spreading the temporarily determined value to generate a re-spread signal;
dividing means for sorting re-spread signal for every directivity, on a per path basis; and
adding means for adding the re-spread signals sorted for every directivity to generate a replica signal.
4. An interference cancellation method for use in a multistage interference cancellation apparatus that removes interference from a directional array combined signal that is received by an array antenna and array combined on a directivity-by-directivity basis, said method comprising, in an interference canceling unit, the steps of:
inputting a plurality of array combined signals subjected to array combining on a directivity-by-directivity basis to select an array-combined signal corresponding to a path;
detecting a correlation value between the selected array combined signal and a spread code;
combining detected correlation values to generate a combined value;
temporarily determining the combined value to generate a temporarily determined value;
re-spreading the temporarily determined value to generate a re-spread signal;
sorting re-spread signals or every directivity, on a per path basis; and
adding the re-spread signals sorted for every directivity to generate a replica signal.