Patent ID: 8068874
Filing Date: 2011-11-29
Classification: H04W

Abstract:
1. A wireless base station including a center unit and a remote unit provided with an array antenna having a plurality of antenna elements, the center unit being coupled with the remote unit through an optical fiber, wherein the center unit comprises: a modulator for converting bit information of a transmission packet into a base band modulated signal; and a first interface for converting the base band modulated signal output from the modulator into an optical signal and transmitting the optical signal to the optical fiber, wherein the remote unit comprises: a second interface for converting the optical signal received from the optical fiber into an electric signal and outputting the electric signal; a signal processor unit for converting the base band modulated signal received as the electric signal from the second interface into a plurality of transmission signals corresponding to the antenna elements of the array antenna and outputting the transmission signal; a Radio Frequency (RF) unit for converting the respective transmission signals output from the signal processor unit into the transmission signals in an RF band and supplying the transmission signals to the antenna elements of the array antenna; and a deviation detector for detecting deviations that are localized within the remote unit and that occurred among the transmission signals supplied to the respective antenna elements of the array antenna, wherein the modulator of the center unit outputs array weight information generated in an update cycle longer than a packet transmission cycle, in parallel to the base band modulated signal, wherein the first interface transmits to the optical fiber an optical signal in which the base band modulated signal and the array weight information output from the modulator are time multiplexed, wherein the second interface separates the electric signal into the base band modulated signal and the array weight information to output the base band signal and the array weight information in parallel, wherein the signal processor unit stores the array weight information received from the second interface in a memory, reads out from the memory a specific array weight information corresponding to the transmission packet, converts the base band signal received from the second interface into a plurality of transmission signals weighted in accordance with the specific array weight information and optimizes the array weight information in the memory or the plurality of transmission signals in accordance with the deviations detected by the deviation detector, wherein the signal processor unit of the remote unit generates a probe signal, and adds the probe signal to each of the plurality of transmission signals in order to supply probe signals to the antenna elements of the array antenna along with the transmission signals through the RF unit, and wherein the deviation detector extracts the probe signals from the transmission signals supplied to the respective antenna elements of the array antenna, and detects the deviations that are localized within the remote unit and that occurred among the transmission signals based on the detected probe signals.