Method and apparatus for a 1 MHZ long training field design

An apparatus comprising:

• at least one processor;
• and
• at least one memory including computer program code for one or more programs,
• the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following:
• determine a preamble sequence of a packet, the preamble sequence having a determinable length;
• cause, at least in part, the preamble sequence to be divided into a predetermined number of blocks;
• cause, at least in part, a mathematical operation and a summation over the predetermined number of blocks and a corresponding number of received blocks;
• and
• cause, at least in part, the summation to be maximized to classify the preamble sequence corresponds to one of a first bandwidth or a second bandwidth, the second bandwidth being greater than the first bandwidth, to determine a type of the packet, wherein the classification of the preamble sequence is based, at least in part, on an equation
• ∑
• k
• i
• ⁢
• (
• p
• ⁢
• ⁢
• p
• k
• +
• 1
• *
• ⁢
• )
• ,
• (
• q
• k
• ⁢
• q
• k
• +
• 1
• *
• )
• *
• =
• 0
• ,
• where p is the preamble sequence, q is a preamble sequence that corresponds to the first bandwidth or the second bandwidth, and k is the index of summation and wherein k is an integer;
• wherein the predetermined number of blocks are of equal length;
• wherein each of the predetermined number of blocks comprises a number of subcarriers, and a predetermined number of the subcarriers are caused to be nulled so as to generate guard tones;
• wherein the division of the blocks causes, at least in part, a preamble sequence that corresponds to the first bandwidth to be orthogonal with a preamble sequence that corresponds to the second bandwidth where each block is in a differential sense orthogonal.

A method comprising:

• determining a preamble sequence of a packet, the preamble sequence having a determinable length;
• and
• causing, at least in part, the preamble sequence to be divided into a predetermined number of blocks,
• wherein the division of the blocks causes, at least in part, a preamble sequence that corresponds to a first bandwidth to be orthogonal with a preamble sequence that corresponds to a second bandwidth where each of the blocks is in a differential sense orthogonal;
• wherein the orthogonality of each of the blocks is based, at least in part, on an equation
• ∑
• k
• i
• ⁢
• (
• p
• ⁢
• ⁢
• p
• k
• +
• 1
• *
• ⁢
• )
• ,
• (
• q
• k
• ⁢
• q
• k
• +
• 1
• *
• )
• *
• =
• 0
• ,
• where p is the preamble sequence that corresponds to a first bandwidth, q is the preamble sequence that corresponds to a second bandwidth, and k is the index of summation and wherein k is an integer.

A non-transitory computer-readable storage medium carrying one or more sequences of one or more instructions which, when executed by one or more processors, cause an apparatus to at least perform the following:

• determine a preamble sequence of a packet, the preamble sequence having a determinable length;
• cause, at least in part, the preamble sequence to be divided into a predetermined number of blocks;
• cause, at least in part, a mathematical operation and a summation over the predetermined number of blocks and a corresponding number of received blocks;
• and
• cause, at least in part, the summation to be maximized to determine the preamble sequence corresponds to one of a first bandwidth or a second bandwidth, the second bandwidth being greater than the first bandwidth, to determine a type of the packet;
• wherein the division of the blocks causes, at least in part, a preamble sequence that corresponds to the first bandwidth to be orthogonal with a preamble sequence that corresponds to the second bandwidth where each block is in a differential sense orthogonal;
• wherein the orthogonality of each of the blocks is based, at least in part, on an equation
• ∑
• k
• i
• ⁢
• (
• p
• ⁢
• ⁢
• p
• k
• +
• 1
• *
• ⁢
• )
• ,
• (
• q
• k
• ⁢
• q
• k
• +
• 1
• *
• )
• *
• =
• 0
• ,
• where p is the preamble sequence that corresponds to a first bandwidth, q is the preamble sequence that corresponds to a second bandwidth, and k is the index of summation and wherein k is an integer.