Orthogonal frequency division multiplexing transmit diversity system for frequency-selective fading channels

Apparatus for use in a wireless communication system to realize transmit diversity including first and second frequency domain signals to be transmitted comprising:

• a time domain signal generator for generating first and second time domain signals representative of said first and second frequency domain signals, respectively;
• a reverse order complex conjugate generator for generating a third time domain signal representative of a reverse order complex conjugate of said first time domain signal;
• a reverse order, reverse sign (−) complex conjugate generator for generating a fourth time domain signal representative of a reverse order, reverse sign (−) complex conjugate of said second time domain signal;
• pairing apparatus for pairing selected components of said first through fourth time domain signals in prescribed time intervals for transmission, whereby transmit diversity is provided for frequency-fading channels in the wireless communication system;
• and
• a first antenna and at least a second antenna for transmitting said time domain signals,
• wherein said pairing apparatus includes at least a first controllable selector for controllably selecting signal components of said first time domain signal for transmission on said first antenna during first time intervals and for controllably selecting signal components of said fourth time domain signal for transmission on said first antenna during second time intervals, and a second controllable selector for controllably selecting signal components of said second time domain signal for transmission on said second antenna during first time intervals and for controllably selecting signal components of said third time domain signal for transmission on said second antenna during second time intervals.

Apparatus for use in a wireless communication system to realize transmit diversity including first and second frequency domain signals to be transmitted comprising:

• means for generating a third frequency domain signal representative of a complex conjugate of said first frequency domain signal;
• means for generating a fourth frequency domain signal representative of a reverse sign (−) complex conjugate of said second frequency domain signal;
• means for generating first through fourth time domain signals representative of said first through fourth frequency domain signals, respectively;
• first antenna means and at least a second antenna means for transmitting said time domain signals;
• and
• means for pairing selected components of said first through fourth time domain signals in prescribed time intervals for transmission, whereby transmit diversity is provided for frequency-fading channels in the wireless communication system,
• wherein said means for pairing apparatus includes at least a first controllable selector means for controllably selecting signal components of said first time domain signal for transmission on said first antenna means during first time intervals and for controllably selecting signal components of said fourth time domain signal for transmission on said first antenna means during second time intervals and a second controllable selector means for controllably selecting signal components of said second time domain signal for transmission on said second antenna means during first time intervals and for controllably selecting signal components of said third time domain signal for transmission on said second antenna means during second time intervals.

Apparatus for use in a wireless communication system to realize transmit diversity including first and second frequency domain signals to be transmitted comprising:

• means for generating first and second time domain signals representative of said first and second frequency domain signals, respectively;
• means for generating a third time domain signal representative of a reverse order complex conjugate of said first time domain signal;
• means for generating a fourth time domain signal representative of a reverse order, reverse sign (−) complex conjugate of said second time domain signal;
• a first antenna means and at least a second antenna means for transmitting said time domain signals;
• and
• means for pairing selected components of said first through fourth time domain signals in prescribed time intervals for transmission, whereby transmit diversity is provided for frequency-fading channels in the wireless communication system,
• wherein said means for pairing apparatus includes at least a first controllable selector means for controllably selecting signal components of said first time domain signal for transmission on said first antenna means during first time intervals and for controllably selecting signal components of said fourth time domain signal for transmission on said first antenna means during second time intervals, and a second controllable selector means for controllably selecting signal components of said second time domain signal for transmission on said second antenna means during first time intervals and for controllably selecting signal components of said third time domain signal for transmission on said second antenna means during second time intervals.

Apparatus for use in a wireless communication system to realize transmit diversity through antenna-group hopping including first and second frequency domain signals to be transmitted comprising:

• a complex conjugate generator for generating a third frequency domain signal representative of a complex conjugate of said first frequency domain signal;
• a reverse sign (−) complex conjugate generator for generating a fourth frequency domain signal representative of a reverse sign (−) complex conjugate of said second frequency domain signal;
• first selection apparatus for selecting prescribed frequency components of said first through fourth frequency domain signals for inclusion into a plurality of frequency domain signals having a selected prescribed relationship to a plurality of antennas including at least three antennas, said selected prescribed relationship being such that two antennas are assigned to each of a plurality of frequency subchannels for transmission of signals;
• a convertor for converting said plurality of frequency domain signals into a corresponding plurality of time domain signals;
• and
• second selection apparatus for selecting prescribed ones of said plurality of time domain signals in prescribed time intervals for transmission, whereby transmit diversity is provided for frequency-fading channels in the wireless communication system.

Apparatus for use in a wireless communication system to realize transmit diversity through antenna hopping including first and second frequency domain signals to be transmitted comprising:

• means for generating a third frequency domain signal representative of a complex conjugate of said first frequency domain signal;
• means for generating a fourth frequency domain signal representative of a reverse sign (−) complex conjugate of said second frequency domain signal;
• first means for selecting prescribed frequency components of said first through fourth frequency domain signals for inclusion into a plurality of frequency domain signals having a selected prescribed relationship to a plurality of antennas including at least three antennas, said selected prescribed relationship being such that two antennas are assigned to each of a plurality of frequency subchannels for transmission of signals;
• means for converting said plurality of frequency domain signals into a corresponding plurality of time domain signals;
• and
• second means for selecting prescribed ones of said plurality of time domain signals in prescribed time intervals for transmission, whereby transmit diversity is provided for frequency-fading channels in the wireless communication system.