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US 2015/0085831 A1Published application
Asymmetrical forward/reverse transmission bandwidth
AssigneeSignal Trust for Wireless Innovation
InventorFatih M. Ozluturk
Life of this patent
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Abstract
A wireless communications system employs code-division multiple access information transmission techniques where the uplink and downlink transmission bandwidths are unequal. The higher bandwidth is an integer multiple of the lower bandwidth. The present system requires a base station and a subscriber unit to have two pseudo-random code generators which can be clocked separately. Alignment of the uplink and downlink pseudo-random spreading codes is achieved by truncating the code sequence for the lower speed link at the conclusion of a complete code sequence for the higher speed link.
Claims20
An apparatus for wireless communication in a code division multiple access (CDMA) system, comprising:
- a first pseudo-random sequence circuit to provide a first pseudo-random code sequence, a second pseudo-random sequence circuit to provide a second pseudo-random code sequence, wherein the second pseudo-random code sequence is longer than the first pseudo-random code sequence;
- and
- a combiner to combine output values associated with the first pseudo-random sequence and associated with the second pseudo-random code sequence to form a third pseudo-random sequence;
- wherein, when the first pseudo-random sequence circuit initializes, the second pseudo-random sequence circuit initializes to truncate the second pseudo-random code sequence, and wherein a length of the first pseudo-random code sequence is a first number of chips, a length of the second pseudo-random code sequence is a second number of chips, the first number of chips being less than the second number of chips, and a length of the third pseudo-random sequence is a third number of chips, the third number of chips being less than a product of the first number of chips and the second number of chips;
- and
- a spreading circuit to spread a signal with the third pseudo-random sequence, wherein the signal carries information.
3 more elements
An apparatus for wireless communication in a code division multiple access (CDMA) system, comprising:
- a first pseudo-random sequence circuit to provide a first pseudo-random code sequence, a second pseudo-random sequence circuit to provide a second pseudo-random code sequence, wherein the second pseudo-random code sequence is longer than the first pseudo-random code sequence;
- and
- a combiner to combine output values associated with the first pseudo-random sequence and associated with the second pseudo-random code sequence to form a third pseudo-random sequence;
- wherein, when the first pseudo-random sequence circuit initializes, the second pseudo-random sequence circuit initializes to truncate the second pseudo-random code sequence, and
- wherein a length of the first pseudo-random code sequence is a first number of chips, a length of the second pseudo-random code sequence is a second number of chips, the first number of chips being less than the second number of chips, and a length of the third pseudo-random sequence is a third number of chips, the third number of chips being less than a product of the first number of chips and the second number of chips;
- and
- a despreading circuit to decode, with the third pseudo-random code sequence, a spread signal, wherein the spread signal carries information.
4 more elements
A method for a wireless terminal in a code division multiple access (CDMA) system, comprising:
- combining, with a mixer, values associated with a first pseudo-random code sequence and associated with a truncated second pseudo-random code sequence into an output code sequence, wherein a period of the first pseudo-random code sequence and a period of the truncated second pseudo-random code sequence are equivalent,
- wherein, when the first pseudo-random sequence initializes, the second pseudo-random sequence initializes to provide the truncated second pseudo-random code sequence, and
- wherein a length of the first pseudo-random code sequence is a first number of chips, a length of the second pseudo-random code sequence is a second number of chips, the first number of chips being less than the second number of chips, and a length of the output code sequence is a third number of chips, the third number of chips being less than a product of the first number of chips and the second number of chips;
- and
- combining, in a circuit, a signal with the output code sequence, wherein the signal carries information.
2 more elements
Apparatus for a wireless terminal in a code division multiple access (CDMA) system, comprising:
- a first combining circuit to combine values associated with a first pseudo-random code sequence and associated with a truncated second pseudo-random code sequence into an output code sequence, wherein a period of the first pseudo-random code sequence and a period of the truncated second pseudo-random code sequence are equivalent,
- wherein, when the first pseudo-random sequence initializes, the second pseudo-random sequence initializes to provide the truncated second pseudo-random code sequence, and
- wherein a length of the first pseudo-random code sequence is a first number of chips, a length of the second pseudo-random code sequence is a second number of chips, the first number of chips being less than the second number of chips, and a length of the output code sequence is a third number of chips, the third number of chips being less than a product of the first number of chips and the second number of chips;
- and
- a second combining circuit to combine a signal with the output code sequence, wherein the signal carries information.
2 more elements
Dependencies are inferred from the claim text.