System and method for antenna diversity using equal power joint maximal ratio combining

A method for communicating between a first communication device and a second communication device using radio frequency (RF) communication techniques, comprising:

• a. applying a transmit weight vector to a baseband signal to be transmitted from the first communication device to the second communication device, the transmit weight vector comprising a complex transmit antenna weight for each of N plurality of antennas as of the first communication device, wherein each complex transmit antenna weight has a magnitude and a phase whose values may vary with frequency across a bandwidth of the baseband signal, thereby generating N transmit signals each of which is weighted across the bandwidth of the baseband signal to be transmitted from corresponding ones of the N plurality of antennas to the second communication device, wherein the magnitude of the complex transmit antenna weight associated with each antenna is such that the power to be output at each antenna is the same and is equal to the total power to be output by all of the N antennas divided by N and such that the sum of the power at each corresponding frequency across the N transmit signals is equal to a constant;
• and;
• b. receiving the N transmit signals at one or more antennas of the second communication device;
• c. determining a receive weight vector comprising a plurality of complex receive antenna weights for the one or more antennas of the second communication device from the signals received by the one or more antennas, wherein each receive antenna weight has a magnitude and a phase whose values may vary with frequency;
• d. computing a transmit weight vector comprising one or more complex transmit antenna weights for the one or more antennas of the second communication device by gain normalizing the receive weight vector and computing a conjugate thereof;
• and
• c. applying to a baseband signal to be transmitted from the second communication device to the first communication device the transmit weight vector associated with the one or more antennas of the second communication device, wherein the transmit weight vector comprises one or more complex transmit antenna weight having a magnitude and a phase whose values may vary with frequency across the bandwidth of the baseband signal to be transmitted, thereby generating one or more transmit signals each of which is weighted across the bandwidth of the baseband signal to be transmitted from a corresponding one or ones of the one or more antennas of the second communication device to the first communication device.

A method for communicating between a first communication device and a second communication device using radio frequency (RF) communication techniques, comprising:

• a. applying a transmit weight vector to a baseband signal to be transmitted from the first communication device to the second communication device, the transmit weight vector comprising a complex transmit antenna weight for each of N plurality of antennas of the first communication device, wherein each complex transmit antenna weight has a magnitude and a phase whose values may vary with frequency across a bandwidth of the baseband signal, thereby generating N transmit signals each of which is weighted across the bandwidth of the baseband signal, wherein the magnitude of the complex transmit antenna weight associated with each antenna is such that the power to be output at each antenna is the same and is equal to the total power to be output by all of the N antennas divided by N and such that the sum of the power at each corresponding frequency across the N transmit signals is equal to a constant;
• b. receiving at the N plurality of antennas of the first communication device one or more signals transmitted by the second communication device;
• c. determining a receive weight vector comprising a plurality of complex receive antenna weights for the N plurality of antennas of the first communication device from the one or more signals received by the N plurality of antennas, wherein each receive antenna weight has a magnitude and a phase whose values may vary with frequency;
• and
• d. updating the transmit weight vector for the N plurality of antennas of the first communication device for transmitting signals to the second communication device by gain normalizing the receive weight vector and computing a conjugate thereof.

A medium encoded with instructions that, when executed, perform a method comprising the steps of:

• a. applying a transmit weight vector to a baseband signal to be transmitted from a first communication device to a second communication device, the transmit weight vector comprising a complex transmit antenna weight for each of N plurality of antennas of the first communication device, wherein each complex transmit antenna weight has a magnitude and a phase whose values may vary with frequency across a bandwidth of the baseband signal, thereby generating N transmit signals each of which is weighted across the bandwidth of the baseband signal, wherein the magnitude of the complex transmit antenna weight associated with each antenna is such that the power to be output at each antenna is the same and is equal to the total power to be output by all of the N antennas divided by N and such that the sum of the power at each corresponding frequency across the N transmit signals is equal to a constant;
• b. from a signal transmitted by a second communication device and received at the plurality of antennas of the first communication device, determining a receive weight vector comprising a plurality of complex receive antenna weights for the N plurality of antennas of the first communication device from the signals received by the N plurality of antennas, wherein each receive antenna weight has a magnitude and a phase whose values may vary with frequency;
• and
• c. updating the transmit weight vector for the N plurality of antennas of the first communication device for transmitting signals to the second communication device by gain normalizing the receive weight vector and computing a conjugate thereof.

A method for communicating between a first communication device and a second communication device using radio frequency (RF) communication techniques, comprising:

• a. applying to a first signal to be transmitted from the first communication device to the second communication device a transmit weight vector, the transmit weight vector comprising a complex transmit antenna weight for each of the N plurality of antennas, wherein each complex transmit antenna weight has a magnitude and a phase whose values may vary with frequency across a bandwidth of the baseband signal, thereby generating N transmit signals each of which is weighted across the bandwidth of the baseband signal, wherein the magnitude of the complex transmit antenna weights associated with each antenna is such that the power to be output at each antenna is the same and is equal to the total power to be output by all of the N antennas divided by N;
• b. transmitting the first signal to the second communication device;
• c. receiving a first response signal at the plurality of antennas of the first communication device transmitted from a first of two antennas of the second communication device;
• d. deriving a first row of a channel response matrix that describes the channel response between the first communication device and the second communication device;
• e. transmitting a second signal by the plurality of antennas of the first communication device using a transmit weight vector that is orthogonal to the first row of the channel response matrix, and wherein the transmit weight vector comprises a plurality of complex transmit antenna weights, wherein each complex transmit antenna weight has a magnitude and a phase whose values may vary with frequency across a bandwidth of the second signal, thereby generating N transmit signals each of which is weighted across the bandwidth of the baseband signal, wherein the magnitude of the complex transmit antenna weights associated with each antenna is such that the power to be output at each antenna is the same and is equal to the total power to be output by all of the N antennas divided by N;
• f. receiving a second response signal transmitted by a second of the two antennas of the second communication device and deriving therefrom a second row of the channel response matrix;
• and
• g. selecting one of the first and second rows of the channel response matrix that provides better signal-to-noise at the second communication device as the transmit weight vector for further transmission of signals to the second communication device.

A medium encoded with instructions, that when, executed perform the method comprising steps of:

• i. applying to a first signal to be transmitted from the first communication device to the second communication device a transmit weight vector, the transmit weight vector comprising a complex transmit antenna weight for each of the N plurality of antennas, wherein each complex transmit antenna weight has a magnitude and a phase whose values may vary with frequency across a bandwidth of the baseband signal, thereby generating N transmit signals each of which is weighted across the bandwidth of the baseband signal, wherein the magnitude of the complex transmit antenna weights associated with each antenna is such that the power to be output at each antenna is the same and is equal to the total power to be output by all of the N antennas divided by N;
• ii. from a first response signal at the plurality of antennas of the first communication device transmitted from a first of two antennas of the second communication device, deriving a first row of a channel response matrix that describes the channel response between the first communication device and the second communication device;
• iii. applying to a second signal for transmission by the plurality of antennas of the first communication device a transmit weight vector that is orthogonal to the first row of the channel response matrix, and wherein the transmit weight vector comprises a plurality of complex transmit antenna weights, wherein each complex transmit antenna weight has a magnitude and a phase whose values may vary with frequency across a bandwidth of the second signal, thereby generating N transmit signals each of which is weighted across the bandwidth of the baseband signal, wherein the magnitude of the complex transmit antenna weights associated with each antenna is such that the power to be output at each antenna is the same and is equal to the total power to be output by all of the N antennas divided by N;
• iv. deriving a second row of the channel response matrix from a second response signal received from a second of the two antennas of the second communication device;
• and
• v. selecting one of the first and second rows of the channel response matrix that provides better signal-to-noise at the second communication device as the transmit weight vector for further transmission of signals to the second communication device.

A radio communication system comprising:

• a. a first communication device having N plurality of antennas, a baseband signal processor that generates N transmit signals and that recovers data from N receive signals and a radio transceiver coupled to the baseband signal processor that upconverts the N transmit signals for transmission via corresponding ones of the N plurality of antennas and downconverts signals received by corresponding ones of the N plurality of antennas to produce the N receive signals, wherein the baseband signal processor of the first communication device applies a transmit weight vector to a baseband signal to be transmitted from the first communication device to the second communication device, the transmit weight vector comprising a complex transmit antenna weight for each of N plurality of antennas of the first communication device, wherein each complex transmit antenna weight has a magnitude and a phase whose values may vary with frequency across a bandwidth of the baseband signal, thereby generating N transmit signals each of which is weighted across the bandwidth of the baseband signal, wherein the magnitude of the complex transmit antenna weight associated with each antenna is such that the power to be output at each antenna is the same and is equal to the total power to be output by all of the N antennas divided by N and such that the sum of the power at each corresponding frequency across the N transmit signals is equal to a constant;
• and
• b. a second communication device having M plurality of antennas, a baseband signal processor that generates M transmit signals and that recovers data from M receive signals and a radio transceiver coupled to the baseband signal processor that upconverts the M transmit signals for transmission via corresponding ones of the M plurality of antennas and downconverts signals received by corresponding ones of the M plurality of antennas to produce the M receive signals, wherein the baseband signal processor of the second communication device:
• determines a receive weight vector comprising complex receive weights for each of the M plurality of antennas from the N transmit signals received by the M plurality of antennas, wherein each receive antenna weight has a magnitude and phase whose values may vary with frequency across a bandwidth of a baseband signal derived from the N transmit signals received by the second communication device;
• computes a transmit weight vector comprising a plurality of complex transmit antenna weights for the M plurality of antennas of the second communication device by computing a conjugate of the receive weight vector divided by the norm of the receive weight vector;
• and applies the transmit weight vector to a baseband signal to be transmitted from the second communication device to the first communication device, thereby generating M plurality of transmit signals such that the power to be output at each antenna is the same and is equal to the total power to be output by all of the M antennas divided by M and such that the sum of the power at each corresponding frequency across the M transmit signals is equal to a constant.

A radio communication device comprising:

• a. N plurality of antennas;
• b. a baseband signal processor that generates transmit signals and that recovers data from receive signals;
• and
• c. a radio transceiver coupled to the baseband signal processor that upconverts the transmit signals for transmission via corresponding ones of the N plurality of antennas and downconverts signals received by corresponding ones of the N plurality of antennas to produce receive signals;
• d. wherein the baseband signal processor applies a transmit weight vector to a baseband signal to be transmitted to another communication device, the transmit weight vector comprising a complex transmit antenna weight for each of the N plurality of antennas, wherein each complex transmit antenna weight has a magnitude and a phase whose values may vary with frequency across a bandwidth of the baseband signal, thereby generating N transmit signals each of which is weighted across the bandwidth of the baseband signal, wherein the magnitude of the complex transmit antenna weights associated with each antenna is such that the power to be output at each antenna is the same and is equal to the total power to be output by all of the N antennas divided by N and such that the sum of the power at each corresponding frequency across the N transmit signals is equal to a constant.