US 7,352,801 B2Granted

Selecting one of multiple antennas to receive signals in a wireless packet network

AssigneeTexas Instruments Incorporated

InventorsSthanunathan Ramakrishnan, Ganesan Thiagarajan

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Abstract

Selecting one of multiple antennas to receive signals in a wireless packet network. Correlation value and gain needed to boost the signal up to a desired power (or the signal strength of the received signal) are determined for each antenna by examining the non-payload portion (e.g., preamble) of the packet. The antenna with the best SNR is then chosen based on the rule given. In an embodiment, the correlation value is determined based on the Barker Sequence employed for each bit in the preamble. The selection may be performed for each data packet, thereby using the antenna receiving the signal most conducive to recovery of the data bits (including payload) in each data packet.

Claims16

Dependent claims

A method of receiving a packet containing a plurality of data symbols, said method being performed in a receiver connected to a plurality of antennas containing a first antenna and a second antenna, said method comprising:

generating a corresponding plurality of parameters by examining a respective signal portion received on each of said plurality of antennas, wherein said signal portion corresponds to a non-payload portion of said packet, said corresponding plurality of parameters comprising a first plurality of parameters and a second plurality of parameters respectively corresponding to said first antenna and said second antenna;
selecting one of said plurality of antennas based on said corresponding plurality of parameters;
and
receiving a payload portion of said packet on said one of said plurality of antennas,
wherein each of said parameters has a corresponding value for each of a plurality of sub-portions of the respective signal portion received on each of said plurality of antennas,
wherein a first parameter contained in each of said corresponding plurality of parameters comprises a correlation value, and a second parameter contained in each of said corresponding plurality of parameters comprises a strength of said signal, said correlation value representing the similarity of said signal portion with a corresponding expected signal according to a pre-defined protocol,
wherein said generating comprises determining a gain factor necessary to amplify said signal portion to a first voltage level, wherein said strength is determined based on said gain factor,
wherein said plurality of antennas comprise only said first antenna and said second antenna, wherein said gain factor for said first antenna and said second antenna is respectively represented by AGC1 and AGC2 on a dB scale, wherein T1 and T2 represent a first threshold and a second threshold,
if a difference in said AGC1 and said AGC2 values is large compared to T1, selecting the antenna having a lower value of said AGC1 and said AGC2;
if the absolute value of said difference between AGC1 and AGC2 values is small, selecting one of said first antenna and said second antenna having a value close to μ∞ if the correlation value of the other one of said two antennas is away from μ∞, wherein μ∞ represents a mean of Gaussian distribution when SNR of said signal is high;
if said AGC1 and said AGC2 are equal, and if said AGC1 and said AGC2 are high, then selecting one of said first antenna and said second antenna having a correlation value closer to μ∞;
and
if said AGC1 and said AGC2 values are equal, and if said AGC1 and said AGC2 are low, selecting one of said first antenna and said second antenna having a higher correlation value.

10 more elements

A receiver for receiving a packet containing a plurality of data symbols, said receiver being connected to a plurality of antennas, said receiver comprising:

a parameters generation block generating a corresponding plurality of parameters by examining a respective signal portion received on each of said plurality of antennas, wherein each of said respective signal portion corresponds to a non-payload portion of said packet, said corresponding plurality of parameters comprising a first plurality of parameters and a second plurality of parameters respectively corresponding to said first antenna and said second antenna;
and
a selector block selecting one of said plurality of antennas based on said corresponding plurality of parameters, wherein a payload portion of said packet is received on said one of said plurality of antennas,
wherein each of said parameters has a corresponding value for each of a plurality of sub-portions of the respective signal portion received on each of said plurality of antennas,
wherein a first parameter contained in each of said corresponding plunility of parameters comprises a correlation value, and a second parameter contained in each of said corresponding plurality of parameters comprises a strength of said signal, said correlation value representing the similarity of said signal portion with a corresponding expected signal according to a pre-defined protocol,
wherein said parameters generation block determines a gain factor necessary to amplify said signal portion to a first voltage level, wherein said strength is determined based on said gain factor in performing said generating,
wherein said plurality of antennas comprise only said first antenna and said second antenna, wherein said gain factor for said first antenna and said second antenna is respectively represented by AGC1 and AGC2 on a dB scale, wherein T1 and T2 represent a first threshold and a second threshold,
if a difference in said AGC1 and said AGC2 values is large compared to T1, selecting the antenna having a lower value of said AGC1 and said AGC2;
if the absolute value of said difference between AGC1 and AGC2 values is small, selecting one of said first antenna and said second antenna having a value close to μ∞ if the correlation value of the other one of said two antennas is away from μ∞, wherein μ∞ represents a mean of Gaussian distribution when SNR of said signal is high;
if said AGC1 and said AGC2 are equal, and if said AGC1 and said AGC2 are high, then selecting one of said first antenna and said second antenna having a correlation value closer to;
and
if said AGC1 and said AGC2 values are equal, and if said AGC1 and said AGC2 are low, selecting one of said first antenna and said second antenna having a higher correlation value.

9 more elements

A device receiving a packet containing a plurality of data symbols, said device comprising:

a first antenna and a second antenna, each receiving a same signal containing a non-payload portion and a payload portion;
a receiver coupled to said plurality of antennas, said receiver comprising:
means for generating a first parameter and a second parameter by examining said non-payload portion received via said first antenna, and a third parameter and a fourth parameter by examining said non-payload portion received via said second antenna, wherein each of said first parameter and said third parameter representing a respective correlation of said non-payload portion with a corresponding expected signal, said second parameter and said fourth parameter representing a respective strength of said signal received via said first antenna and said second antenna;
means for selecting one of said plurality of antennas based on said first parameter, said second parameter, said third parameter and said fourth parameter;
and
means for receiving a payload portion of said packet on said one of said plurality of antennas,
wherein said means for generating determines a gain factor necessary to amplify said signal portion to a first voltage level, wherein said strength is determined based on said gain factor,
wherein said gain factor for said first antenna and said second antenna is respectively represented by AGC1 and AGC2 on a dB scale, wherein T1 and T2 represent a first threshold and a second threshold,
if a difference in said AGC1 and said AGC2 values is large compared to T1, selecting the antenna having a lower value of said AGC1 and said AGC2;
if the absolute value of said difference between AGC1 and AGC2 values is small, selecting one of said first antenna and said second antenna having a value close to μ∞ if the correlation value of the other one of said two antennas is away from μ∞, wherein μ∞ represents a mean of Gaussian distribution when SNR of said signal is high;
if said AGC1 and said AGC2 are equal, and if said AGC1 and said AGC2 are high, then selection one of said first antenna and said second antenna having a xorrelation value closer to;
and
if said AGC1 and said AGC2 values are equal, and if said AGC1 and said AGC2 are low, selecting one of said first antenna and said second antenna having a higher correlation value.

10 more elements

Dependencies are inferred from the claim text.

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Abstract

generating a corresponding plurality of parameters by examining a respective signal portion received on each of said plurality of antennas, wherein said signal portion corresponds to a non-payload portion of said packet, said corresponding plurality of parameters comprising a first plurality of parameters and a second plurality of parameters respectively corresponding to said first antenna and said second antenna;
selecting one of said plurality of antennas based on said corresponding plurality of parameters;
and
receiving a payload portion of said packet on said one of said plurality of antennas,
wherein each of said parameters has a corresponding value for each of a plurality of sub-portions of the respective signal portion received on each of said plurality of antennas,
wherein a first parameter contained in each of said corresponding plurality of parameters comprises a correlation value, and a second parameter contained in each of said corresponding plurality of parameters comprises a strength of said signal, said correlation value representing the similarity of said signal portion with a corresponding expected signal according to a pre-defined protocol,
wherein said generating comprises determining a gain factor necessary to amplify said signal portion to a first voltage level, wherein said strength is determined based on said gain factor,
wherein said plurality of antennas comprise only said first antenna and said second antenna, wherein said gain factor for said first antenna and said second antenna is respectively represented by AGC1 and AGC2 on a dB scale, wherein T1 and T2 represent a first threshold and a second threshold,
if a difference in said AGC1 and said AGC2 values is large compared to T1, selecting the antenna having a lower value of said AGC1 and said AGC2;
if the absolute value of said difference between AGC1 and AGC2 values is small, selecting one of said first antenna and said second antenna having a value close to μ∞ if the correlation value of the other one of said two antennas is away from μ∞, wherein μ∞ represents a mean of Gaussian distribution when SNR of said signal is high;
if said AGC1 and said AGC2 are equal, and if said AGC1 and said AGC2 are high, then selecting one of said first antenna and said second antenna having a correlation value closer to μ∞;
and
if said AGC1 and said AGC2 values are equal, and if said AGC1 and said AGC2 are low, selecting one of said first antenna and said second antenna having a higher correlation value.

10 more elements