Preamble channel decoding
AssigneeQUALCOMM Incorporated
InventorsJoseph P. Odenwalder, Sandip Sarkar, Yongbin Wei
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Abstract
Rather than attaching a preamble to a data traffic subpacket, a preamble channel is transmitted along with a traffic channel. In a system wherein the data traffic subpackets are variably sized, preambles can also be variably sized if a target station can decode variably sized preambles. A method and apparatus for decoding variably sized preamble subpackets are presented herein.
Claims15
An apparatus in a remote station for decoding a preamble channel, wherein the preamble channel carries variably sized preamble sequences, comprising:
- a plurality of preamble size detection elements for determining a number of slots occupied by a preamble sequence on the preamble channel, wherein each of the plurality of preamble size detection elements outputs a potential preamble sequence and a best path metric;
- and
- a selection element for choosing a true preamble sequence from the potential preamble sequences output from the plurality of detection elements.
A method for determining preamble information transmitted on a preamble channel, comprising:
- de-interleaving over one slot of the preamble channel to form a first de-interleaved sequence;
- de-interleaving over at least two slots of the preamble channel to form a second de-interleaved sequence, wherein the first slot of the at least two slots is the slot used in the first de-interleaving step;
- soft-combining the second de-interleaved sequence;
- decoding the first de-interleaved sequence to generate a first potential preamble and a first metric value;
- decoding the second de-interleaved sequence to generate a second potential preamble and a second metric value;
- and
- choosing between the first potential preamble and the second potential preamble to select a true preamble.
A method for determining the preamble information carried by a preamble channel, comprising:
- de-interleaving over a variable number of slots for a plurality of deinterleaving results;
- soft-combining symbols within each of the plurality of de-interleaving results, except in the instance when the de-interleaving is over one slot;
- decoding the one-slot de-interleaved symbol and the soft-combined symbols associated with each of the plurality of de-interleaving results;
- checking the decoded symbols for an identifier;
- and
- extracting the preamble information from the checked symbol that carries the identifier.
An apparatus for determining preamble information transmitted on a preamble channel, comprising:
- means for de-interleaving over one slot of the preamble channel to form a first de-interleaved sequence;
- means for de-interleaving over at least two slots of the preamble channel to form a second de-interleaved sequence, wherein the first slot of the at least two slots is the same slot as the first de-interleaving step;
- means for soft-combining the second de-interleaved sequence;
- means for decoding the first de-interleaved sequence to generate a first potential preamble and a first metric value and for decoding the second de-interleaved sequence to generate a second potential preamble and a second metric value;
- and
- means for choosing between the first potential preamble and the second potential preamble as a true preamble.
An apparatus for determining the preamble information carried by a preamble channel, comprising:
- means for de-interleaving over a variable number of slots for a plurality of de-interleaving results;
- means for soft-combining symbols within each of the plurality of de-interleaving results, except for the de-interleaving result over one slot;
- means for decoding the one-slot de-interleaved symbols and the soft-combined symbols associated with each of the plurality of de-interleaving results;
- means for checking the decoded symbols for an identifier;
- and
- means for extracting the preamble information from the checked symbol carrying the identifier.
Dependencies are inferred from the claim text.