Abstract: A preprocessing apparatus and method for a transmitter and a receiver to prevent system performance degradation caused by Inter-Channel Interference (ICI) or inter-symbol interference (ISI) in an OFDM system. In the OFDM system using N carriers having different frequency bands and K carriers of the N carriers designated as redundant carriers, the transmitter renders ICI-causing parts to be zeroes in a data frame, when a cyclic prefix is not longer than a channel impulse response. Therefore, the ICI is prevented. The receiver eliminates the ISI involved in a current frame using an interference estimated from a previous data frame. Therefore, noise spread caused by the use of redundant carriers is prevented and system complexity is remarkably reduced.

Abstract: A code reuse apparatus in a code division multiple access wireless communication system using beamforming by an antenna array and a code reuse method therefor, wherein the method includes examining a spatial correlation between a new mobile station requesting communication and each of existing mobile stations using already allocated codes, based on long-term information reflecting spatial characteristics of beams transmitted to the new and existing mobile stations, and selecting one among the already allocated codes to reuse as a code for the new mobile station depending on the results of the correlation examination. As a result, the factual number of mobile stations for one base station may be close to the theoretic number of mobile stations corresponding to power gain by beamforming.

Abstract: A mobile communication apparatus with an antenna array and a mobile communication method therefore, wherein the apparatus includes a base station with an antenna array and a mobile station, wherein the mobile station determines a channel downlink characteristic for each antenna, determines long-term information and short-term information, converts the determined long-term information and short-term information to a feedback signal, and transmits the feedback signal to the base station. The base station receives the feedback signal, extracts a plurality of weights from the long-term information and short-term information, multiplies a multiplexed dedicated physical channel signal by the respective weights, adds respective pilot channel signals to the products, and transmits the results of the additions through the antenna array to the mobile station.

Abstract: A mobile communication apparatus having multiple transmission antennas and multiple reception antennas and a mobile communication method used in the mobile communication apparatus, wherein a base station, which has at least one reception antenna, restores long-term and short-term information determined in consideration of first characteristics in a mobile station, which has at least one transmission antenna, from a feedback signal received from the mobile station, spatially processes dedicated physical channel signals using basis information produced from the restored long-term and short-term information, and transmits the results of addition of the spatially-processed signals to pilot signals to the mobile station, wherein the first characteristics are the characteristics of the downlink channels of the respective transmission and reception antennas.

Abstract: A data transmitting/receiving apparatus and method using an antenna array in a mobile communication system. A Node B measures a transmission status of each transmission antenna, classifies transmission data according to priority, and transmits to a UE high-priority data through a transmission antenna at a relatively good transmission status and low-priority data through a transmission antenna at a relatively poor transmission status.

Abstract: A mobile communication apparatus having an antenna array and a mobile communication method performed in the mobile communication apparatus, wherein the mobile communication apparatus includes a base station and mobile station, each having an antenna array. The mobile station measures the downlink characteristics of a channel for each antenna from a signal received from a base station, determines long-term information in which the correlation property of the channel for each antenna has been reflected from the measured downlink characteristics, transforms the long-term information into a feedback signal, and transmits the feedback signal to the base station.

Abstract: Disclosed a transmission apparatus in a CDMA mobile communication system. Transmission frames each have a plurality of time slots, and each of the time slots includes two data parts having the same length, a midamble intervening between the data parts, and a guard period for dividing the consecutive time slots. The transmission apparatus modulates the frames into a radio signal with a modulation signal and transmits the modulated radio signal using a plurality of antennas. A power amplifier amplifies the radio signal. A controller generates a switching control signal in a guard period of time slots of a frame associated with the radio signal amplified by the power amplifier. A switch switches the amplified radio signal from the power amplifier between a first and a second antenna in response to the switching control signal.