Radio LAN station with improved frame delimiter detection in a spread spectrum environment

Claim 2

A radio LAN station for receiving information frames including start and end delimiters, said start and end delimiters including data symbols and non-data symbols, said data symbols and non-data symbols being transmitted via a spread spectrum signal and being spread via first and second spreading codes, respectively, said station comprising: analog to digital conversion means adapted to provide a digital representation of a received spread spectrum signal; first correlating means, coupled to said analog to digital conversion means, for correlating a digital representation of said spread spectrum signal against said first spreading code to produce a rectangular representation of said data symbols; second correlating means, coupled to said analog to digital conversion means, for correlating a digital representation of said spread spectrum signal against said second spreading code to produce a rectangular representation of said non-data symbols; first converting means, coupled to said first correlating means, for converting said rectangular representation of said data symbols into a polar representation of said data symbols to produce a vector length Z representative thereof; second converting means, coupled to said second correlating means, for converting said rectangular representation of said non-data symbols into a polar representation of said non-data symbols to produce a vector length Z' representative thereof; and means for determining that a symbol is a data symbol if Z--Z' is greater than or equal to a constant A, or that a symbol is a non-data symbol if Z--Z1 is less than said constant A, such that the data and non-data symbols representing said start and end delimiters are detected.

Claim 3

A radio LAN station for receiving information frames including start and end delimiters, said start and end delimiters including data symbols and non-data symbols, said data symbols and non-data symbols being transmitted via a spread spectrum signal and being spread via first and second spreading codes, respectively, said station comprising: down-converting means for down-converting said spread spectrum signal to produce a down-converted spread spectrum signal; analog to digital conversion means, coupled to said down-converting means, for providing a digital representation of said down-converted spread spectrum signal; first correlating means, coupled to said analog to digital conversion means, for correlating a digital representation of said down-converted spread spectrum signal against said first spreading code to produce a rectangular representation of said data symbols; second correlating means, coupled to said analog to digital conversion means, for correlating a digital representation of said down-converted spread spectrum signal against said second spreading code to produce a rectangular representation of said non-data symbols; first converting means, coupled to said first correlating means, for converting said rectangular representation of said data symbols into a polar representation of said data symbols to produce a vector length Z representative thereof; second converting means, coupled to said second correlating means, for converting said rectangular representation of said non-data symbols into a polar representation of said non-data symbols to produce a vector length Z' representative thereof; and comparing means, coupled to said first and second converting means, for comparing said vector lengths Z and Z' to determine that a symbol is a data symbol if Z--Z' is greater or equal to a constant A, or that a symbol is a non-data symbol if Z--Z1 is less than said constant A, such that the data and non-data symbols representing said start and end delimiters are detected.

Claim 4

A radio LAN station for receiving information frames including start and end delimiters, said start and end delimiters including data symbols and non-data symbols, said data symbols and non-data symbols being transmitted via a spread spectrum signal and being spread via first and second spreading codes, respectively, said station comprising: down-converting means for down-converting said spread spectrum signal to produce a down-converted spread spectrum signal; analog to digital conversion means, coupled to said down-converting means, for providing a digital representation of said down-converted spread spectrum signal; first correlating means, coupled to said analog to digital conversion means, for correlating a digital representation of said down-converted spread spectrum signal against said first spreading code to produce a rectangular representation of said data symbols; second correlating means, coupled to said analog to digital conversion means, for correlating a digital representation of said down-converted spread spectrum signal against said second spreading code to produce a rectangular representation of said non-data symbols; first converting means, coupled to said first correlating means, for converting said rectangular representation of said data symbols into a polar representation of said data symbols to produce a vector length Z representative thereof; second converting means, coupled to said second correlating means, for converting said rectangular representation of said non-data symbols into a polar representation of said non-data symbols to produce a vector length Z' representative thereof; and comparing means, coupled to said first and second converting means, for comparing said vector lengths Z and Z' to determine that a symbol is a data symbol if Z--Z' is greater or equal to a constant A, or that a symbol is a non-data symbol if Z--Z1 is less than said constant A, such that the data and non-data symbols representing said start and end delimiters are detected.

Claim 11

The method of claim 5 and further including the steps of: receiving said data signals and said non-data signals in said spread spectrum radio signal in a sequential format; correlating said spread spectrum radio signal to said first spreading code to recover said data signals; and correlating said spread spectrum radio signal to said second spreading code to recover said non-data signals.

Claim 12

A radio receiver for receiving a spread spectrum signal comprising: first receiving means for receiving data signals transmitted in said spread spectrum signal; and second receiving means, coupled to said first receiving means, for receiving non-data signals transmitted in said spread spectrum signal, non-data signals being generally orthogonal to said data signals and further being sequentially received with respect to said data signals.

Claim 13

A radio receiver for receiving a spread spectrum signal comprising: first receiving means for receiving data signals transmitted in said spread spectrum signal; and second receiving means, coupled to said first receiving means, for receiving non-data signals transmitted in said spread spectrum signal, non-data signals being generally orthogonal to said data signals and further being sequentially received with respect to said data signals.

Claim 14

A radio receiver for local area network comprising: an input to which a spread spectrum signal is provided; first receiving means, coupled to said input, for receiving data signals transmitted in said spread spectrum signal and including means for recovering said data signals from said spread spectrum signal, said data signals being spread by a first spreading code; and second receiving means, coupled to said input, for receiving non-data signals transmitted in said spread spectrum signal and including means for recovering said non-data signals, said non-data signals being spread by a second spreading code, said non-data signals being generally orthogonal to said data signals and further being sequentially recovered with respect to said data signals.

Claim 15

A radio receiver for local area network comprising: an input to which a spread spectrum signal is provided; first receiving means, coupled to said input, for receiving data signals transmitted in said spread spectrum signal and including means for recovering said data signals from said spread spectrum signal, said data signals being spread by a first spreading code; and second receiving means, coupled to said input, for receiving non-data signals transmitted in said spread spectrum signal and including means for recovering said non-data signals, said non-data signals being spread by a second spreading code, said non-data signals being generally orthogonal to said data signals and further being sequentially recovered with respect to said data signals.

Claim 16

The radio receiver of claim 8 wherein said first receiving means includes first correlating means for correlating said spread spectrum signal to said first spreading code to recover said data signals.

Claim 17

The radio receiver of claim 9 wherein said second receiving means includes second correlating means for correlating said spread spectrum signal to said second spreading code to recover said non-data signals.