Wireless communication apparatus and method
First Claim
1. A method of achieving transmit diversity gain for frequency selective fading channels in a communication system having a base station with multiple transmit antennae and a mobile terminal with at least a single receive antenna, the method comprising the steps of:
- providing a signal to be transmitted s(n);
space-time encoding the signal s(n) to produce at least two separate signals s1(n),s2(n), each on a respective output;
feeding each output signal s1(n),s2(n) to a zero-forcing pre-equaliser having a respective function g1(k), g2(k) to produce an output signal x1(n),x2(n);
feeding the output signal x1(n),x2(n) of each pre-equaliser to a transmit antenna;
transmitting the output signals x1(n),x2(n) over respective physical channels h1(k), h2(k);
receiving the output signals x1(n),x2(n) at at least a single receive antenna; and
space-time decoding the received signals, wherein the functions g1(k),g2(k) of the zero-forcing pre-equalisers are selected such that the channel responses g1(k)*h1(k),g2(k)*h2(k) of the respective physical channels h1(k),h2(k) are flat fading channels.
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Accused Products
Abstract
A method and apparatus for achieving combined beamforming and transmit diversity for frequency selective fading channels in a communication system having a base station with multiple transmit antennae and a mobile terminal with at least a single receive antenna, the method comprising the steps of: providing a signal to be transmitted; space-time encoding the signal to produce at least two separate signals, each on a respective output; feeding each output signal to a multiple access transmit processor to produce an output signal; applying respective selected transmit beamforming weights to each output signal; feeding the respective weighted signals to a signal combiner to perform a summing function of the signals and produce a signal for transmission; feeding the summed signal to each of the multiple transmit antennae for transmission; transmitting the signals over respective physical channels; receiving the transmitted signal at at least a single receive antenna; feeding the transmitted signal to a multiple access receive processor to produce an output signal; and space-time decoding the received signal.
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Citations
45 Claims
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1. A method of achieving transmit diversity gain for frequency selective fading channels in a communication system having a base station with multiple transmit antennae and a mobile terminal with at least a single receive antenna, the method comprising the steps of:
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providing a signal to be transmitted s(n);
space-time encoding the signal s(n) to produce at least two separate signals s1(n),s2(n), each on a respective output;
feeding each output signal s1(n),s2(n) to a zero-forcing pre-equaliser having a respective function g1(k), g2(k) to produce an output signal x1(n),x2(n);
feeding the output signal x1(n),x2(n) of each pre-equaliser to a transmit antenna;
transmitting the output signals x1(n),x2(n) over respective physical channels h1(k), h2(k);
receiving the output signals x1(n),x2(n) at at least a single receive antenna; and
space-time decoding the received signals, wherein the functions g1(k),g2(k) of the zero-forcing pre-equalisers are selected such that the channel responses g1(k)*h1(k),g2(k)*h2(k) of the respective physical channels h1(k),h2(k) are flat fading channels. - View Dependent Claims (2, 3, 4, 5)
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6. A base station with multiple transmit antennae for communicating with a mobile terminal having at least a single receive antenna over physical channels h1(k), h2(k), the base station comprising:
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a space-time encoder having an input of a signal to be transmitted s(n) and at least two outputs each producing a separate signal s1(n),s2(n);
at least two zero-forcing pre-equalisers, each fed by a respective output signal s1(n),s2(n) and having a respective function g1(k), g2(k) to produce an output signal x1(n), x2(n); and
at least two transmit antennae, each being fed by the output signal x1(n),x2(n) of a respective one of the pre-equalisers, wherein the functions g1(k),g2(k) of the zero-forcing pre-equalisers are selected such that the channel responses g1(k)*h1(k), g2(k)*h2(k) of the respective physical channels h1(k), h2(k) are flat fading channels. - View Dependent Claims (7)
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8. A method of achieving combined beamforming and transmit diversity for frequency selective fading channels in a communication system having a base station with multiple transmit antennae and a mobile terminal with at least a single receive antenna, the method comprising the steps of:
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providing a signal to be transmitted S(n;
k);
space-time encoding the signal S(n;
k) to produce at least two separate signals S1(n;
k),S2(n;
k), each on a respective output;
feeding each output signal S1(n;
k),S2(n;
k) to a transmit processor to produce an output signal X1(n;
k), X2(n;
k);
applying respective selected transmit beamforming weights to each output signal X1(n;
k), X2(n;
k);
feeding the respective weighted signals to a signal combiner to perform a summing function of the signals and produce a signal X(n;
k) for transmission;
feeding the summed signal X(n;
k) to each of the multiple transmit antennae for transmission;
transmitting the signals X(n;
k) over physical channel h(n;
k);
receiving the received signal Y(n;
k) at at least a single receive antenna;
feeding the received signal Y(n;
k) to a receive processor to produce an output signal; and
space-time decoding the received signal. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 29)
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24. A base station with multiple transmit antennae for communicating with a mobile terminal having at least a single receive antenna over physical channel h(k), the base station comprising:
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a space-time encoder having an input of a signal to be transmitted and at least two outputs each producing a separate signal;
at least two transmit processors each receiving one of the outputs from a respective space-time encoder;
at least two transmit beamformers each receiving an output from a respective transmit processor and applying a transmit beamforming weight thereto;
a signal combiner receiving signals from the beamformers and operable to perform a summing function of the signals from the beamformers and produce a signal for transmission by the multiple transmit antennae. - View Dependent Claims (25, 26, 27, 28, 30, 45)
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31. A method of achieving combined beamforming and transmit diversity for frequency selective fading channels in a communication system having a base station with multiple transmit antennae and a mobile terminal with at least a single receive antenna, the method comprising the steps of:
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providing a signal to be transmitted s(n);
space-time encoding a signal to be transmitted s(n) to produce at least two separate signals s1(n),s2(n), each on a respective output;
delaying one of the space-time encoded output signals by Δ
τ
;
applying respective selected transmit beamforming weights to the delayed and undelayed signals;
feeding the respective weighted signals to a signal combiner to perform a summing function of the signals and produce a signal for transmission;
feeding the summed signal to each of the multiple transmit antennae for transmission;
transmitting the summed signals over the physical channel h(k);
receiving the major components of the transmitted signals at at least a single receive antenna at substantially the same time; and
space-time decoding the received signal. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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44. A base station with multiple transmit antennae for communicating with a mobile terminal having at least a single receive antenna over physical channel h(k) having two time-delayed rays, h1(k) and h2(k), the base station comprising:
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a space-time encoder having an input of a signal to be transmitted and at least two outputs each producing a separate signal;
at least two transmit beamformers each receiving an output from the space-time encoder and applying a transmit beamforming weight thereto;
a signal combiner receiving signals from the beamformers and operable to perform a summing function of the signals from the beamformers and produce a signal for transmission by each of the multiple transmit antennae, wherein a delay of Δ
τ
is interposed between the space-time encoder and one of the beamformers such that the major components of the transmitted signals are received at at least a single receive antenna at substantially the same time.
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Specification