Data transmission apparatus for DS/CDMA system equipped with MIMO antenna system
A transmission apparatus for a DS/CDMA system including a multiple-input multiple output MIMO antenna system is disclosed. The apparatus includes a transmitter for transmitting data by applying a different scramble code to each transmitted data through a plurality of transmitting antennas. The apparatus also includes a receiver for receiving the transmitted data by obtaining a diversity gain based on the maximum order of the diversity in order to effectively detect the data. The present invention achieves an excellent detection performance by receiving data with a full order of diversity, which is a multiple of the number of receiving antennas and the number of multipath, without complicated operation such as a decision feed equalizer.
1. A receiving apparatus for a direct sequence (DS)/code division multiple access (CDMA) system equipped with a multiple-input multiple-output (MIMO) antenna system, comprising:
a plurality of receiving antennas for receiving a signal transmitted from a transmitter;
input signal generating means for gathering transmitted data in the received signal and outputting the gathered transmitted data;
adaptive filtering means for filtering a complex received signal according to a tap weight which is controlled in a predetermined cycle, and outputting filtered data;
channel estimating means for estimating a phase and an amplitude of a channel between one of a plurality of transmitting antennas and one of a plurality of receiving antennas based on the filtered data, and outputting an estimation data as a result of estimation;
signal recovering means for recovering an original signal from the received signal by combining the estimation data and filtered data with all components of multipath;
selecting means for selecting one of the original signal and a training data signal supplied by the receiver and outputting a selected signal;
reference signal generating means for generating a reference signal based on the selected signal and the estimation data;
error calculating means for calculating error between the filtered data and the reference signal by subtracting the filtered data from the reference signal multiplied by the estimation data; and
tap weight controlling means for controlling the tap weight of the adaptive filtering unit based on a constraint minimum mean square error (MMSE) criterion having at least one condition.
2. A transmission and receiving apparatus for a direct sequence (DS)/code division multiple access (CDMA) system equipped with a multiple-input multiple-output (MIMO) antenna system, comprising:
serial to parallel converting means for converting serially inputted high speed data to parallel data sequences;
spreading means for spreading the parallel data sequences based on spreading codes, which are orthogonal to each other, to generate a plurality of spread data sequences;
pilot signal spreading means for spreading pilot signals to generate a plurality of spread pilot signals;
combining means for combining each of the spread data sequences and each of the spread pilot signals, to generate a plurality of combined data sequences;
scrambling means for scrambling each of the combined data sequences by using a different scrambling code in order to generate scrambled data;
a plurality of transmitting antennas for independently transmitting the scrambled data;
a plurality of receiving antennas for receiving the scrambled data transmitted from the transmitting antennas;
input signal generating means for gathering transmitted data in the received signal and outputting the gathered transmitting data;
adaptive filtering means for filtering a complex received signal according to a tap weight which is controlled in a predetermined cycle, and outputting filtered data;
channel estimating means for estimating a phase and an amplitude of a channel between one of the transmitting antennas and one of the receiving antennas based on the filtered data, and outputting estimation data as a result of estimation;
signal recovering means for recovering an original signal from the received signal by combining the estimation data and filtered data with all components of multipath;
selecting means for selecting one of the original signal and a training data signal supplied by the receiver, and outputting a selected signal;
reference signal generating means for generating a reference signal based on the selected signal and the estimation data;
error calculating means for calculating error between the filtered data and the reference signal by subtracting the filtered data from the reference signal multiplied by the estimation data; and
tap weight controlling means for controlling the tap weight of the adaptive filtering unit based on a constraint minimum mean square error (MMSE) criterion having at least one condition.