Systems, methods, and devices for interference mitigation in wireless networks

A non-transitory computer-readable medium storing computer-executable instructions which when executed by one or more processors result in performing operations comprising:

• receiving, by a first device for performing multiple input, multiple output (MIMO) channel estimation using a long training field (LTF) of a high efficiency (HE) frame received over one or more spatial streams, wherein the LTF comprises one or more LTF symbols, and wherein a first LTF symbol of the one or more LTF symbols and a second LTF symbol of the one or more LTF symbols are associated with two or more subcarriers;
• identifying the first LTF symbol by applying a first orthogonal code entry of a p-matrix comprising one or more orthogonal code entries to a first subcarrier of the two or more subcarriers associated with the one or more LTF symbols, wherein the first orthogonal code entry corresponds to a spatial stream of the one or more spatial streams, wherein the first LTF symbol is associated with a first frequency;
• identifying the second LTF symbol by applying the first orthogonal code entry to a second subcarrier of the two or more subcarriers, wherein the second LTF symbol is associated with a second frequency, wherein the first frequency is different from the second frequency;
• and
• enabling the MIMO channel estimation of a MIMO channel between a set of receive chains on the first device and a set of outputs on a second device that sent the HE frame.

A method for generating, at a first device, a high efficiency (HE) frame comprising a long training field (LTF) that includes one or more LTF symbols, wherein a first LTF symbol of the one or more LTF symbols and a second LTF symbol of the one or more LTF symbols are associated with two or more subcarriers, the HE frame to be sent to a receiver across one or more spatial streams, the method comprising:

• determining, by one or more processors of the first device, a p-matrix comprising one or more orthogonal code entries, wherein a first orthogonal code entry of the one or more orthogonal code entries corresponds to a spatial stream of the one or more spatial streams;
• generating, by the one or more processors, the first LTF symbol by applying a first subcarrier of the two or more subcarriers to the first orthogonal code entry, wherein the first LTF symbol is associated with a first frequency;
• generating, by the one or more processors, the second LTF symbol by applying a second subcarrier of the two or more subcarriers to the first orthogonal code entry, wherein the second LTF symbol is associated with a second frequency, wherein the first frequency is different from the second frequency;
• generating, by the one or more processors, the LTF of the HE frame, wherein the LTF comprises the first LTF symbol and the second LTF symbol;
• and
• causing to send, by the one or more processors, the HE frame across the one or more spatial streams.