Method for transmitting multi-antenna superimposed symbol and apparatus using the same

A method for transmitting symbols in a communication system, the method comprising:

• dividing N symbols to be transmitted at substantially the same time into a first group and a second group, performing a first processing on each of a plurality of symbols in the first group to obtain a first group of superimposed symbols, and performing a second processing on each of a plurality of symbols in the second group to obtain a second group of superimposed symbols;
• and
• transmitting each of the first group of superimposed symbols by a first antenna, and transmitting corresponding symbols in the second group of superimposed symbols by a second antenna, wherein the first processing and the second processing respectively include a conjugate cancellation operation,
• wherein the conjugate cancellation operation includes a weighted operation and a conjugate operation, and
• wherein when N equals 4, the symbols transmitted by the first antenna at Timing i+2, i+1 and i are:
• bs3, as1+bs3 and −(cs2*+ds4*) respectively, where a, b, c and d are respectively complex constants, “*” indicates the conjugate operation, and, s1 to s4 are respectively serial numbers of the symbols to be transmitted.

An apparatus for transmitting symbols in a communication system, comprising:

• a receiver configured to receive symbols;
• a coder configured to encode the received symbols, and
• a plurality of antennas configured to transmit coded symbols;
• the coder further configured to divide N symbols to be transmitted at substantially the same time into a first group and a second group, perform a first processing on each of a plurality of symbols in the first group to obtain a first group of superimposed symbols, and perform a second processing on each of a plurality of symbols in the second group to obtain a second group of superimposed symbols, and wherein a first antenna is configured to transmit each of the first group of superimposed symbols one by one, and a second antenna is configured to transmit corresponding symbols in the second group of superimposed symbols, and wherein the first processing and the second processing respectively include a conjugate cancellation operation, wherein the conjugate cancellation operation includes a weighted operation and a conjugate operation, and
• wherein when N equals 8, the symbols transmitted by the first antenna at Timing i+2, i+1 and i are:
• cs3+ds4, as1+bs2+cs3+ds4 and −(e*s5*+f*s6*+g*s7*+h*s8*) respectively, where a˜b, c, d˜e, f˜g and h are respectively complex constants, “*” indicates the conjugate operation, and s1 to s8 are respectively serial numbers of the symbols to be transmitted.

An apparatus for transmitting symbols in a communication system, comprising:

• a receiver configured to receive symbols;
• a coder configured to encode the received symbols, and
• a plurality of antennas configured to transmit coded symbols;
• the coder further configured to divide N symbols to be transmitted at substantially the same time into a first group and a second group, perform a first processing on each of a plurality of symbols in the first group to obtain a first group of superimposed symbols, and perform a second processing on each of a plurality of symbols in the second group to obtain a second group of superimposed symbols, and wherein a first antenna is configured to transmit each of the first group of superimposed symbols, and a second antenna is configured to transmit corresponding symbol in the second group of superimposed symbols, and wherein the first processing and the second processing respectively include a conjugate cancellation operation,
• wherein the conjugate cancellation operation includes a weighted operation and a conjugate wherein when N equals to 4, the symbols transmitted by the first antenna at Timing i+2,i+1 and i are bs3, as1+bs3 and −(cs2+ds4) respectively, where a, b, c and d are respectively complex constants, “*” indicates the conjugate operation, and, s1 and s4 are respectively serial numbers of the symbols to be transmitted.