Systems and methods for resource allocation to multiple antenna arrays for maintaining a constant bit rate (CBR) channel

• US 20060018288A1
• Filed: 01/24/2005
• Published: 01/26/2006
• Est. Priority Date: 01/22/2004
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Luo, Wenjun, El Zarki, Magda, Zan, Lei
• Granted Patent: US 7,430,190 B2
• Time in Patent Office: Days
• US Class Current: 370/334
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04L 27/20 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 52/267 taking into account the information rate
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity
• CPC Class Codes: H04W 72/04 Wireless resource allocation

Abstract

A wireless communication system configured for the efficient allocation of resources is provided. The wireless communication system can include a transmit system having a first set of one or more antennas each configured to transmit a data signal over a region to a receive system having a second set of two or more antennas each configured to receive the transmitted data signal. The transmit system can be configured to adjust a transmission parameter of a data signal based on a level of signal fading in the region to sustain a target bit rate, adjust a power and a bit rate at which a data signal is transmitted based on the level of signal fading in the region and select a subset of antennas within the first set of antennas to be used to transmit a data signal based on the level of signal fading in the region.

Claims

1. A wireless communication system, comprising:

a transmit system comprising a first set of two or more antennas, the transmit system being configured to transmit a data signal from each of two or more of the antennas in the first set over a region; and

a receive system comprising a second set of two or more antennas each configured to receive the two or more transmitted data signals, wherein the transmit system is configured to adjust a transmission parameter of at least one data signal based on the level of signal fading in the region to maintain a target communication bit rate.

2. The system of claim 1, wherein the level of signal fading is determined by the level of multipath fading and the level of time-variable fading.

3. The system of claim 1, wherein the transmission parameter comprises a power at which at least one data signal is transmitted.

4. The system of claim 1, wherein the transmission parameter comprises a bit rate at which at least one data signal is transmitted.

5. The system of claim 1, wherein the transmit system is further configured to select a subset of antennas from the first set of antennas from which to transmit the data signals.

6. The system of claim 1, wherein the number of antennas in the second set of antennas is greater than or equal to the number of antennas in the first set of antennas.

7. The system of claim 1, wherein the target communication bit rate of is a bit rate for a sustainable bit rate (SBR) conduit.

8. The system of claim 7, wherein the transmit system is configured to adjust a first transmission parameter and a second transmission parameter, wherein the first transmission parameter is a power at which the data signal is transmitted and the second transmission parameter is a bit rate at which the data signal is transmitted.

9. The system of claim 8, wherein the transmit system is configured to transmit the data signal in quadrature amplitude modulated (QAM) format and to adjust the second transmission parameter according to:

K_i=[log₂(−

λ

)−

log₂(const·

ln 2[C⁺C]<sup>−

1</sup>_ji)]⁺

wherein Ki is the number of bits represented by a QAM symbol sent from antenna i and is representative of the bit rate at which the data signal is transmitted from antenna i,

wherein C is representative of the transfer matrix of the region, const is determined by;

const=−

ln(5BER_target)·

N₀/1.5

wherein BER_target is a target bit error rate in the one or more transmitted data signals, N₀ is representative of the noise in the region and A is determined by;

Σ

[log₂(−

λ

)−

log₂(const·

ln 2·

[C⁺C]<sup>−

1</sup>_ji)]⁺=target bit rate×

T_{symbol period}

wherein T_{symbol period} is the period of a symbol in the respective data signal, and wherein the transmit system is configured to adjust the first transmission parameter according to;

$\begin{array}{c}{\mathrm{Es}}_i=\mathrm{const}·<br><br>\left(\frac{-\mathrm{\lambda <br><br>}}{\mathrm{const}·<br><br>\ln <br><br>\text{\hspace{1em}<br><br>}<br><br>2·<br><br>{\left[C^{+}<br><br>C\right]}_{\mathrm{ii}}^{-1}}-1\right)·<br><br>{\left[C^{+}<br><br>C\right]}_{\mathrm{ii}}^{-1}\\ =\frac{-\mathrm{\lambda <br><br>}}{\ln <br><br>\text{\hspace{1em}<br><br>}<br><br>2}-\mathrm{const}·<br><br>{\left[C^{+}<br><br>C\right]}_{\mathrm{ii}}^{-1}\end{array}$

wherein Es_i is representative of the power at which the data signal is transmitted from antenna i.

10. The system of claim 8, wherein the transmission parameter is a power at which the data signal is transmitted and wherein the transmit system is configured to transmit the data signal in quadrature amplitude modulated (QAM) format and to adjust transmission parameter according to:

11. The system of claim 1, wherein the transmit system is configured to budget power.

12. A wireless communication system, comprising:

a transmit system comprising a first set of two or more antennas, the transmit system being configured to transmit a data signal from each of two or more of the antennas in the first set over a region; and

a receive system comprising a second set of two or more antennas each configured to receive the two or more transmitted data signals, wherein the transmit system is configured to adjust a power at which at least one data signal is transmitted and a bit rate at which at least one data signal is transmitted based on a level of signal fading in the region.

13. The system of claim 12, wherein the transmit system is further configured to select a subset of antennas from the first set of antennas from which to transmit the data signals.

14. The system of claim 12, wherein the number of antennas in the second set of antennas is greater than or equal to the number of antennas in the first set of antennas.

15. The system of claim 12, wherein the transmit system is configured to adjust the power and bit rate to maintain a target rate of communication.

16. The system of claim 15, wherein the target rate of communication is a bit rate for a sustainable bit rate (SBR) conduit.

17. The system of claim 16, wherein the transmit system is configured to transmit the data signal in quadrature amplitude modulated (QAM) format and to adjust the second transmission parameter according to:

K_i=[log₂(−

λ

)−

log₂(const·

ln 2·

[C⁺C]<sup>−

1</sup>_ji)]⁺

wherein Ki is the number of bits represented by a QAM symbol sent from antenna i and is representative of a bit rate at which the data signal is transmitted from antenna i,

wherein C is representative of the transfer matrix of the region, const is determined by;

const·

ln(5BER_target)·

N₀/1.5

wherein BER_target is a target bit error rate in the one or more transmitted data signals, N₀ is representative of the noise in the region and λ

is determined by;

Σ

[log₂(−

λ

)−

log₂(const·

ln 2[C⁺C]<sup>−

1</sup>_ji)]⁺=target bit rate×

T_{symbol period}

wherein T_{symbol period} is the period of a symbol in the respective data signal, and wherein the transmit system is configured to adjust the first transmission parameter according to;

$\begin{array}{c}{\mathrm{Es}}_i=\mathrm{const}·<br><br>\left(\frac{-\mathrm{\lambda <br><br>}}{\mathrm{const}·<br><br>\ln <br><br>\text{\hspace{1em}<br><br>}<br><br>2·<br><br>{\left[C^{+}<br><br>C\right]}_{\mathrm{ii}}^{-1}}-1\right)·<br><br>{\left[C^{+}<br><br>C\right]}_{\mathrm{ii}}^{-1}\\ =\frac{-\mathrm{\lambda <br><br>}}{\ln <br><br>\text{\hspace{1em}<br><br>}<br><br>2}-\mathrm{const}·<br><br>{\left[C^{+}<br><br>C\right]}_{\mathrm{ii}}^{-1}\end{array}$

wherein Es_i is representative of the power at which the data signal is transmitted from antenna i.

18. The system of claim 16, wherein the transmission parameter is a power at which the data signal is transmitted and wherein the transmit system is configured to transmit the data signals in quadrature amplitude modulated (QAM) format and to adjust the power at which at least one data signal is transmitted according to:

19. A wireless communication system, comprising:

a transmit system comprising a first set of two or more antennas each configured to transmit a data signal over a region; and

a receive system comprising a second set of two or more antennas each configured to receive the transmitted data signals from the first set of antennas,

wherein the transmit system is configured to select a subset of two or more antennas from the first set based on the level of signal fading in the region and transmit at least one data signal from each antenna in the subset.

20. The system of claim 19, wherein the subset is a first subset and the receive system is further configured to select a second subset of two or more antennas from the second set based on the level of signal fading in the region and use the second subset of antennas to receive the transmitted data signals.

21. The system of claim 19, wherein the transmit system is further configured to adjust a transmission parameter of at least one data signal based on the level of signal fading in the region.

22. The system of claim 21, wherein the transmission parameter is a first transmission parameter comprising a power at which the data signal is transmitted and wherein the transmit system is further configured to adjust a second transmission parameter comprising a bit rate at which the data signal is transmitted.

23. The system of claim 19, wherein the transmit system is configured to select the subset of antennas to maintain a target rate of communication.

24. The system of claim 23, wherein the target rate of communication is a bit rate for a sustainable bit rate (SBR) conduit.

25. The system of claim 24, wherein the transmit system is configured to adjust a power at which the data signal is transmitted and a bit rate at which the data signal is transmitted, and wherein the transmit system is configured to transmit the data signal in quadrature amplitude modulated (QAM) format and to adjust the bit rate according to:

K_i=[log₂(−

λ

)−

log₂(const·

ln 2[C⁺C]<sup>−

1</sup>_ji)]⁺

wherein Ki is the number of bits represented by a QAM symbol sent from antenna i and is representative of the bit rate at which the data signal is transmitted from antenna i,

wherein C is representative of the transfer matrix of the region, const is determined by;

const=−

ln(5BER_target)·

N₀/1.5

wherein BER_target is a target bit error rate in the one or more transmitted data signals, N₀ is representative of the noise in the region and λ

is determined by;

Σ

[log₂(−

λ

)−

log₂(const·

ln 2[C⁺C]<sup>−

1</sup>_ji)]⁺=target bit rate×

T_{symbol period}

wherein T_{symbol period} is the period of a symbol in the respective data signal, and wherein the transmit system is configured to adjust the power according to;

${\mathrm{Es}}_i=\mathrm{const}·<br><br>\left(\frac{-\mathrm{\lambda <br><br>}}{\mathrm{const}·<br><br>\ln <br><br>\text{\hspace{1em}<br><br>}<br><br>2·<br><br>{\left[C^{+}<br><br>C\right]}_{\mathrm{ii}}^{-1}}-1\right)·<br><br>{\left[C^{+}<br><br>C\right]}_{\mathrm{ii}}^{-1}=\frac{-\mathrm{\lambda <br><br>}}{\ln <br><br>\text{\hspace{1em}<br><br>}<br><br>2}-\mathrm{const}·<br><br>{\left[C^{+}<br><br>C\right]}_{\mathrm{ii}}^{-1}$

wherein Es_i is representative of the power at which the data signal is transmitted from antenna i.

26. The system of claim 24, wherein the transmission parameter is a power allocation to the antenna and wherein the transmit system is configured to transmit the data signal in quadrature amplitude modulated (QAM) format and to adjust the transmission parameter according to: