Apparatus and method for space-time block coding for increasing coding gain

A method of space-time block coding in a transmitter having a plurality of transmit antennas, comprising the steps of:

• pre-coding an input symbol sequence by multiplying the input symbol sequence by ejθ, θ being calculated as a phase rotation angle by
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• into a pre-coded symbol sequence being reconstructed to have real and imaginary parts;
• generating symbol vectors by recombining the real and imaginary parts of the pre-coded symbol sequence using an interleaving scheme;
• encoding the symbol vectors using an Alamouti scheme;
• and
• transmitting the Alamouti encoded symbol vectors through the plurality of transmit antennas.

A transmitter having four transmit antennas in a system using a space-time block coding scheme, the transmitter comprising:

• a pre-coder for pre-coding an input symbol sequence by multiplying the input symbol sequence by ejθ, θ being a phase rotation angle, in case of QPSK in range of 0≦θ≦90, 23.5≦θ≦24.5, or 65.5≦θ≦66.5, in case of 16QAM in range of 0≦θ≦90, 15.5≦θ≦17.5 or 72.5≦θ≦74.5, into a pre-coded symbol sequence being reconstructed to have real and imaginary parts;
• a mapper for generating symbol vectors by recombining the real and imaginary parts of the pre-coded symbol sequence using an interleaving scheme;
• and
• a plurality of Alamouti coders for encoding the symbol vectors using an Alamouti scheme and transmitting the encoded symbol vectors through the four transmit antennas.

A transmitter having four transmit antennas in a system using a space-time block coding scheme, comprising:

• a pre-coder for pre-coding an input symbol sequence by multiplying the input symbol sequence by ejθ, θ being a phase rotation angle, in case of QPSK in range of 90<θ, 23.5+90n≦θ≦24.5+90n, or 65.5+90n≦θ≦66.5+90n, in case of 16QAM in range of 90<θ, 15.5n≦θ≦17.5n, or 72.5n≦θ≦74.5n, where n is an integer, into a pre-coded symbol sequence being reconstructed to have real and imaginary parts;
• a mapper for generating symbol vectors by recombining the real and imaginary parts of the pre-coded symbol sequence using an interleaving scheme;
• and
• a plurality of Alamouti coders for encoding the symbol vectors using an Alamouti scheme and transmitting the encoded symbol vectors through the four transmit antennas.

A transmitter having an even number of transmit antennas in a system using a space-time block coding scheme, the transmitter comprising:

• a pre-coder for pre-coding an input symbol sequence by multiplying even columns of the input symbol sequence by exp(jθ1) and multiplying odd columns of the input symbol sequence by exp(jθ2) according to a predetermined modulation scheme, into a pre-coded symbol sequence being reconstructed to have real and imaginary parts;
• a mapper for generating symbol vectors by recombining the real and imaginary parts of the pre-coded symbol sequence using an interleaving scheme;
• and
• a plurality of Alamouti coders for encoding the symbol vectors using an Alamouti scheme and transmitting the encoded symbol vectors through the four transmit antennas.

A space-time block coding method in a transmitter having a plurality of transmit antennas, comprising the steps of:

• pre-coding an input symbol sequence by multiplying the input symbol sequence by ejθ, θ being a phase rotation angle, in case of QPSK in range of 0≦θ≦90, 23.5≦θ≦24.5, or 65.5≦θ≦66.5, in case of 16QAM in range of 0≦θ≦90, 15.5≦θ≦17.5, or 72.5≦θ≦74.5, into a pre-coded symbol sequence being reconstructed to have real and imaginary parts;
• generating symbol vectors by recombining the real and imaginary parts of the pre-coded symbol sequence using an interleaving scheme;
• encoding the symbol vectors using an Alamouti scheme;
• and
• transmitting the encoded symbol vectors through corresponding transmit antennas.

A method of space-time block coding in a transmitter with four transmit antennas, comprising the steps of:

• pre-coding an input symbol sequence by multiplying the input symbol sequence by ejθ, θ being a phase rotation angle, in case of QPSK in range of 90<θ, 23.5+90n≦θ≦24.5+90n, or 65.5+90n≦θ≦66.5+90n, in case of 16QAM in range of 90<θ, 15.5n≦0≦17.5n, or 72.5n≦0≦74.5n, where n is an integer, into a pre-coded symbol sequence being reconstructed to have real and imaginary parts;
• generating symbol vectors by recombining the real and imaginary parts of the pre-coded symbol sequence using an interleaving scheme;
• encoding the symbol vectors using an Alamouti scheme;
• and
• transmitting the encoded symbol vectors through corresponding transmit antennas.

A method of space-time block coding in a transmitter with an even number of transmit antennas, comprising the steps of:

• pre-coding an input symbol sequence by multiplying even columns of the input symbol sequence by exp(jθ1) and multiplying odd columns of the input symbol sequence by exp(jθ2) according to a predetermined modulation scheme, into a pre-coded symbol sequence being reconstructed to have real and imaginary parts;
• generating symbol vectors by recombining the real and imaginary parts of the pre-coded symbol sequence using an interleaving scheme;
• encoding the symbol vectors using an Alamouti scheme;
• and
• transmitting the encoded symbol vectors through the transmit antennas.