Methods and apparatus for improving acquisition for nfc load modulation

Abstract

Aspects disclosed herein relate to improving acquisition for NFC load modulation. In one example, a communications device is equipped to monitor at least a complex component of load modulation of a carrier signal, detect, using a NFC technology type specific peak detection scheme, a peak associated with at least the complex component, and determine a presence of a packet beginning pattern based on the detected peak. In an aspect, the packet beginning pattern may be associated with a reception of a packet from a target NFC device.

1 . An apparatus for communication, comprising:
 means for monitoring, by an initiator near-field communication (NFC) device using NFC-type A, at least a complex component of load modulation of a carrier signal;   means for detecting a plurality of local peaks above a threshold magnitude associated with at least the complex component;   means for determining whether a peak of the plurality of local peaks has a magnitude, or magnitude squared, greater than a fraction of a sum of magnitude, or magnitude squared, of a Nth future local peak and a magnitude, or magnitude squared, of a (N+K)th future local peak; and   means for determining a presence of a packet-beginning pattern based on the detected plurality of local peaks, wherein the packet-beginning pattern is associated with a reception of a packet from a target NFC device.   
     
     
         2 . The apparatus of  claim 1 ,
 wherein the Nth future local peak is a first future local peak,   wherein the (N+K)th future local peak is a fourth future local peak, and   wherein the packet beginning pattern is a start of communication (SoC) pattern.   
     
     
         3 . An apparatus for communication, comprising:
 means for monitoring, by an initiator near-field communication (NFC) device using NFC-type A, at least a complex component of load modulation of a carrier signal;   means for detecting a plurality of local peaks above a threshold magnitude associated with at least the complex component;   means for determining whether a peak of the plurality of local peaks has a magnitude, or magnitude squared, greater than a magnitude, or magnitude squared, of any of a future set of N local peaks; and   means for determining a presence of a packet-beginning pattern based on the detected plurality of local peaks, wherein the packet-beginning pattern is associated with a reception of a packet from a target NFC device.   
     
     
         4 . An apparatus for communication, comprising:
 means for monitoring, by an initiator near-field communication (NFC) device using NFC-type F, at least a complex component of load modulation of a carrier signal;   means for detecting a peak associated with at least the complex component, said means for detecting comprising:
 means for detecting a first peak using a binary matched filter and an associated threshold, 
 means for detecting a second peak using a matched filter, said detecting by the matched filter being triggered by the detecting of the first peak by the binary matched filter; and 
   means for determining a presence of a packet-beginning pattern based on the detected first and second peaks, wherein the packet-beginning pattern is associated with a reception of a packet from a target NFC device.   
     
     
         5 . An apparatus for communication, comprising:
 means for monitoring, by an initiator near-field communication (NFC) device using NFC-type B, at least a complex component of load modulation of a carrier signal;   means for detecting a plurality of local peaks above a threshold magnitude associated with at least the complex component;   means for determining whether a peak of the plurality of local peaks has a magnitude, or magnitude squared, greater than a sum of magnitude, or magnitude squared, of a Nth future local peak and a magnitude, or magnitude squared, of a (N+K)th future local peak; and   means for determining a presence of a packet-beginning pattern based on the detected plurality of local peaks, wherein the packet-beginning pattern is associated with a reception of a packet from a target NFC device.   
     
     
         6 . The apparatus of  claim 5 , wherein the Nth future local peak is a 15th local peak, and wherein the (N+K)th future local peak is a 16th local peak, and wherein the packet beginning pattern is associated with transition between TR 1  and T Listen,S1 . 
     
     
         7 . An apparatus for communication, comprising:
 means for monitoring, by an initiator near-field communication (NFC) device using NFC-type Vicinity, at least a complex component of load modulation of a carrier signal;   means for detecting a plurality of local peaks above a threshold magnitude associated with at least the complex component;   means for determining whether a peak of the plurality of local peaks has a magnitude or magnitude squared greater than a magnitude, or magnitude squared, of any of a future set of N local peaks; and   means for determining a presence of a packet-beginning pattern based on the detected plurality of local peaks, wherein the packet-beginning pattern is associated with a reception of a packet from a target NFC device.   
     
     
         8 . A non-transitory computer-readable medium storing computer-executable code for communication comprising:
 code for monitoring, by an initiator near-field communication (NFC) device using NFC-type A, at least a complex component of load modulation of a carrier signal;   code for detecting a plurality of local peaks above a threshold magnitude associated with at least the complex component;   code for determining whether a peak of the plurality of local peaks has a magnitude, or magnitude squared, greater than a fraction of a sum of magnitude, or magnitude squared, of a Nth future local peak and a magnitude, or magnitude squared, of a (N+K)th future local peak; and   code for determining a presence of a packet-beginning pattern based on the detected plurality of local peaks, wherein the packet-beginning pattern is associated with a reception of a packet from a target NFC device.   
     
     
         9 . The computer-readable medium of  claim 8 ,
 wherein the Nth future local peak is a first future local peak,   wherein the (N+K)th future local peak is a fourth future local peak, and   wherein the packet beginning pattern is a start of communication (SoC) pattern.   
     
     
         10 . A non-transitory computer-readable medium storing computer-executable code for communication, comprising:
 code for monitoring, by an initiator near-field communication (NFC) device using NFC-type A, at least a complex component of load modulation of a carrier signal;   code for detecting a plurality of local peaks above a threshold magnitude associated with at least the complex component;   code for determining whether a peak of the plurality of local peaks has a magnitude, or magnitude squared, greater than a magnitude, or magnitude squared, of any of a future set of N local peaks; and   code for determining a presence of a packet-beginning pattern based on the detected plurality of local peaks, wherein the packet-beginning pattern is associated with a reception of a packet from a target NFC device.   
     
     
         11 . A non-transitory computer-readable medium storing computer-executable code for communication, comprising:
 code for monitoring, by an initiator near-field communication (NFC) device using NFC-type F, at least a complex component of load modulation of a carrier signal;   code for detecting a peak associated with at least the complex component, said code for detecting comprising:
 code for detecting a first peak using a binary matched filter and an associated threshold, 
 code for detecting a second peak using a matched filter, said detecting by the matched filter being triggered by the detecting of the first peak by the binary matched filter; and 
   code for determining a presence of a packet-beginning pattern based on the detected first and second peaks, wherein the packet-beginning pattern is associated with a reception of a packet from a target NFC device.   
     
     
         12 . A non-transitory computer-readable medium storing computer-executable code for communication, comprising:
 code for monitoring, by an initiator near-field communication (NFC) device using NFC-type B, at least a complex component of load modulation of a carrier signal;   code for detecting a plurality of local peaks above a threshold magnitude associated with at least the complex component;   code for determining whether a peak of the plurality of local peaks has a magnitude, or magnitude squared, greater than a sum of magnitude, or magnitude squared, of a Nth future local peak and a magnitude, or magnitude squared, of a (N+K)th future local peak; and   code for determining a presence of a packet-beginning pattern based on the detected plurality of local peaks, wherein the packet-beginning pattern is associated with a reception of a packet from a target NFC device.   
     
     
         13 . The computer-readable medium of  claim 12 , wherein the Nth future local peak is a 15th local peak, and wherein the (N+K)th future local peak is a 16th local peak, and wherein the packet beginning pattern is associated with transition between TR 1  and T Listen,S1 . 
     
     
         14 . A non-transitory computer-readable medium storing computer-executable code for communication, comprising:
 code for monitoring, by an initiator near-field communication (NFC) device using NFC-type Vicinity, at least a complex component of load modulation of a carrier signal;   code for detecting a plurality of local peaks above a threshold magnitude associated with at least the complex component;   code for determining whether a peak of the plurality of local peaks has a magnitude or magnitude squared greater than a magnitude, or magnitude squared, of any of a future set of N local peaks; and   code for determining a presence of a packet-beginning pattern based on the detected plurality of local peaks, wherein the packet-beginning pattern is associated with a reception of a packet from a target NFC device.