초록 ▼

In a base station which has a plurality of antennas, each of a plurality of comparison circuits operates to compare correlation levels, which are obtained by despreading received signals for a plurality of channels, with each other with respect to the antennas. Each of a plurality of transmission an

In a base station which has a plurality of antennas, each of a plurality of comparison circuits operates to compare correlation levels, which are obtained by despreading received signals for a plurality of channels, with each other with respect to the antennas. Each of a plurality of transmission antenna selecting circuits operates to determine from which antenna a transmission signal is to be transmitted for every channel. Each of a plurality of multiplexing circuits operates to multiplex the transmission signals of the individual channels, which are spread, for every antenna. As a result, on the basis of the result of the comparison of the correlation levels with respect to the antennas, a transmission antenna is selected for every channel, and the signals of the channels that are to be transmitted by a given antenna are multiplexed, whereby the base station achieves transmission diversity.

대표청구항 ▼

[ We claim:] [29.] A CDMA/TDD (Code Division Multiple Access/Time Division Duplex) base station, comprising:a plurality of antennas;despreading means for subjecting signals received by each of said antennas to despreading for each of a plurality of channels;comparison means for comparing correlation

[ We claim:] [29.] A CDMA/TDD (Code Division Multiple Access/Time Division Duplex) base station, comprising:a plurality of antennas;despreading means for subjecting signals received by each of said antennas to despreading for each of a plurality of channels;comparison means for comparing correlation levels for each channel with respect to each antenna, which correlation levels are obtained by said despreading means, to determine which antennas have received which channels best;transmission antenna selecting means for selecting, on the basis of output signals from said comparison means, for every channel, one of said antennas from which a transmission signal is to be transmitted outwardly; andmultiplexing means for multiplexing the transmission signals of associated channels which are selected for transmission by the same antenna, for every antenna..Iaddend..Iadd.30. A CDMA/TDD base station according to claim 29, further comprising means for estimating, from changes in past values of the correlation levels, future values of the correlation levels with the code..Iaddend..Iadd.31. A CDMA/TDD base station according to claim 29, wherein all of said plurality of antennas of said base station are adjacently arranged in a central portion of a cover area of said base station..Iaddend..Iadd.32. A CDMA/TDD base station according to claim 29, wherein said plurality of antennas of said base station are distributively arranged in a plurality of locations within a cover area of said base station..Iaddend..Iadd.33. A CDMA/TDD base station according to claim 29, wherein said plurality of antennas of said base station are divided into a plurality of antenna groups, each antenna group having a plurality of antennas, wherein the plurality of antennas in each of said antenna groups are adjacently arranged, and wherein said antenna groups are distributively arranged at a plurality of locations within a cover area of said base station..Iaddend..Iadd.34. A CDMA/TDD base station according to claim 29, wherein in said transmission antenna selecting means, antennas are selected for individual channels independently of the selection for other channels..Iaddend..Iadd.35. A CDMA/TDD base station according to claim 29, wherein said transmission antenna selecting means adjusts the selection of antennas for the channel so as to avoid selecting only a subset of antennas out of all of said antennas..Iaddend..Iadd.36. A CDMA/TDD base station according to claim 29, wherein:said multiplexing means has a multiplexing capability corresponding to a number of channels which does not exceed a constant (M) that is smaller than the total number of channels (L) within a cover area of said base station;said base station further comprises radio transmission/reception means provided for every antenna which has an amplification capability to accommodate the number of channels which does not exceed said constant (M); andsaid transmission antenna selecting means selects antennas for the channels so that the number of channels selected for any one of the antennas not to eed said constant (M)..Iaddend..Iadd.37. A CDMA/TDD base station according to claim 29, in combination with a CDMA/TDD mobile station that communicates with said base station..Iaddend..Iadd.38. A CDMA/TDD mobile communication method, comprising the steps of:(a) subjecting signals received by each of a plurality of antennas to despreading for each of a plurality of channels;(b) comparing correlation levels for each channel with respect to each antenna, which correlation levels are obtained by said despreading, to determine which antennas have received which channels best; and(c) selecting, on the basis of said comparing step, for every channel, one of said antennas from which a transmission signal is to be transmitted outwardly..Iaddend..Iadd.39. A method according to claim 38, further comprising the step of multiplexing transmission signals that were selected in step (c) for transmission by the same antenna..Iaddend..Iadd.40. A method according to claim 38, wherein step (c) comprises estimating, from changes in past values of the correlation levels, future values of the correlation levels with the code..Iaddend..Iadd.41. A method according to claim 38, wherein step (c) comprises adjusting the selection of antennas for the channels so as to avoid selecting only a subset of antennas out of all of said antennas..Iaddend..Iadd.42. A method according to claim 38, wherein step (c) comprises adjusting the selection of antennas for the channels so as to avoid selecting the same antenna for more than a predetermined number of channels..Iaddend..Iadd.43. A CDMA/TDD base station for communication with mobile stations over a plurality of channels, each channel having a code assigned to it, comprising:a plurality of antennas;a plurality of receiving units, each receiving unit corresponding to one of the antennas and receiving a signal via the corresponding antenna during a sequence of reception time slots;means for despreading the signal received by each receiving unit using the codes assigned to all of the channels to thereby provide a set of despread signals corresponding to each antenna;a plurality of transmission units, each transmission unit corresponding to one of the antennas;means for spreading transmission data for each of the channels; andmeans, responsive to the sets of despread signals, for selectively distributing the spread transmission data to the transmission units for transmission via the corresponding antennas during transmission time slots that are interspersed with the reception time slot..Iaddend..Iadd.44. A CDMA/TDD base station according to claim 43, in combination with a CDMA/TDD mobile station that communicates with said base station..Iaddend.