What is claimed is:
1. A base transceiver station for use in communication with a plurality of radio mobile station apparatuses based on code division multiple access, comprising a reception signal interference canceller device,
the interference canceller device comprising:
a slot configuration circuit for dividing a reception signal at certain time intervals, converting the divided signal into signals at a faster cycle and converting into a signal having a serial slot configuration as many the converted signals as stages for stage processing on a signal identical to the converted signals at a faster cycle;
a correlation circuit for performing a despreading process on the signal having the slot configuration;
a stage addition circuit for adding the number of stages for stage processing to the despread signals;
a re-spreading circuit for performing a re-spreading process on the signals which have been subjected to the stage addition;
a synthesis circuit for performing a process of synthesizing all of the spread signals which have been subjected to the re-spreading process to generate replica signals; and
a subtraction process circuit for performing a subtraction process between the replica signals and the reception signals,
wherein signals obtained by subtraction process for the replica signals and the reception signals are repeatedly fed back to the correlation circuit thereby to eliminate an interference component.
2. A base transceiver station according to claim 1, wherein the slot configuration circuit divides the reception signal at certain time intervals such that one of the divided signals partially overlaps another divided signal at a signal dividing point.
3. A base transceiver station according to claim 1, wherein among the signals having a serial slot configuration, with respect to the slot signal to be despread:
before being inputted to the correlation circuit, only a first slot thereof is allowed to pass through and the rest of the slots is disallowed to pass; and
the signal whose second slot and subsequent slots are subjected to an interference cancellation process and then fed-back, is inputted into the correlation circuit.
4. A base transceiver station according to claim 1, wherein the stage addition circuit selects valid signals out of the despread signals inputted thereto, selects signals to be added, and selects signals to be re-spread and further selects the despread signals for controlling selections thereof and adding.
5. A base transceiver station according to claim 1, wherein:
the correlation circuit comprises a shift register, despread code setting elements and a matched filter having an addition circuit; and
in correlation detection for outputting a correlation value signal by sequentially shifting the reception signals inputted to the shift register to the subsequent stages, and meanwhile integrating with the despread code setting elements, and adding the integrated signals, the matched filter conducts correlation detection by switching despread codes set in the despread code setting element within the period during which the signals in the shift register are shifted to the subsequent stages, and performs a despreading process for a plurality of users.
6. A base transceiver station according to claim 1, wherein the path detection circuit comprises:
a selector for selecting pilot signal portions at the beginning of the correlation value signals outputted by the correlation circuit;
an averaging circuit for performing an averaging process on the selected pilot signals among the slot signals;
an accumulation circuit for performing accumulation of the averaged pilot signals and the slot signals in the subsequent stages;
a forgetful averaging circuit for performing a forgetful averaging process between the accumulatively added signals and other accumulatively added signals in the subsequent stages;
a path detectionpeak detection circuit for detecting paths for the reception signals from the correlation value signals which have been subjected to the forgetful averaging process and detecting the peaks and positions of valid paths; and
a despread signal detection circuit for detecting despread signals from the correlation value signals based on the information of valid paths detected by the path detectionpeak detection circuit.
7. A method for eliminating interference components in a reception signal, comprising the steps of:
receiving a signal transmitted by a radio mobile base station;
dividing the reception signal at certain time intervals, converting the divided signal into signals at a faster cycle and converting the thus obtained signals into a signal having a serial slot configuration and including as many signals identical to the thus obtained signals as the number of stages for stage processing;
performing a despreading process on the signal having the slot configuration and a feedback signal;
adding the number of stages for stage processing despread signals obtained by the despreading process;
performing a despreading process on the signals which have been subjected to the stage addition;
performing a process of synthesizing all of the spread signals obtained by the re-spreading process to generate replica signals; and
performing a subtraction process between the replica signals and reception signals and generating the feedback signal to output signals which have been subjected to the stage addition.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-28. (canceled)
29. An optical identification element comprising a non-waveguide optical substrate having a volume and including an inner region surrounded by an outer region, the inner region having an index of refraction that prevents the optical substrate from forming an optical waveguide and the optical substrate including a diffraction grating within the volume, the grating providing an output signal indicative of a code when illuminated by an incident light.
30. The element in accordance with claim 29 wherein the inner region and the outer region extend along an axis, the outer region surrounding the inner region about the axis.
31. The element in accordance with claim 29 wherein the inner and outer regions are made of a common material.
32. The element in accordance with claim 29 wherein the inner region has an index of refraction less than or equal to the outer region.
33. The element in accordance with claim 29 wherein the inner region includes the diffraction grating therein or thereon.
34. The element in accordance with claim 29 wherein the diffraction grating is a Bragg grating.
35. The element in accordance with claim 29 wherein the inner region is a photosensitive inner region.
36. The element in accordance with claim 29 wherein the grating provides the output signal when illuminated from outside the substrate.
37. The element in accordance with claim 29 wherein the inner region includes a geometric center of the substrate.
38. The element in accordance with claim 29 wherein the index of refraction of the outer region is uniform throughout the outer region.
39. A method for reading an optical identification element comprising:
obtaining an optical identification element that includes a non-waveguide optical substrate having a volume and an inner region surrounded by an outer region, the inner region having an index of refraction that prevents the optical substrate from forming an optical waveguide and the optical substrate including a diffraction grating within the volume;
illuminating the grating with an incident light, the grating providing an output signal indicative of a code; and
reading the output signal.
40. The method in accordance with claim 39 wherein illuminating the grating includes illuminating the grating from outside the substrate.
41. The method in accordance with claim 39 wherein the inner region and the outer region extend along an axis, the outer region surrounding the inner region about the axis.
42. The method in accordance with claim 39 wherein the inner and outer regions are made of a common material.
43. The method in accordance with claim 39 wherein the inner region has an index of refraction less than or equal to the outer region.
44. The method in accordance with claim 39 wherein the inner region includes the diffraction grating therein or thereon.
45. The method in accordance with claim 39 wherein the diffraction grating is a Bragg grating.
46. The method in accordance with claim 39 wherein the index of refraction of the outer region is uniform throughout the outer region.
47. The method in accordance with claim 39 wherein the inner region includes a geometric center of the substrate.
48. The method in accordance with claim 39 wherein the inner region is a photosensitive inner region.