Patent ID: 9363128
Filing Date: 2016-06-07
CPC Classification: H04B,H04J,H04L

Claim Text:
1. A machine-implemented method of detecting packets at a receiving system in a Multi-Carrier Modulation (MCM) system, wherein packets are transmitted through the MCM system, wherein each transmitted packet includes a preamble for packet detection, wherein the preamble for each packet consists of a plurality of carriers without modulation, and wherein the plurality of carriers are transmitted in a plurality of symbol durations, the method comprising: receiving a signal at the receiving system; obtaining a set of phases of the signal for each symbol duration in the plurality of symbol durations, wherein each phase is a phase of a carrier of the plurality of carriers; obtaining a set of phase variances for each carrier of the plurality of carriers, wherein each phase variance is a difference of phases of a carrier in different symbol durations, wherein a phase variance of a carrier is derived using a mean phase of the carrier computed over a plurality of past symbols; computing a phase variance value based on the set of phase variances, wherein the computing the phase variance value includes selecting a subset of the set of phase variances, wherein the subset of the set of phase variances is selected by excluding phase variances of one or more carriers of the plurality of carriers from computing the phase variance value; and comparing the phase variance value with a threshold to determine whether a packet has been detected from the received signal.