Method and apparatus for minimizing false detection of packet data in a communication receiver

An apparatus for minimizing false detection of packet data in a receiver due to noise in a communication system utilizing data packet time slots that have a nominal predetermined timing for receipt, wherein some of the time slots contain a transmitted signal comprising a data packet, while others of the time slots contain only noise, and wherein the data packet comprises a sync word and an error-detecting code word, the apparatus comprising:

• a first synchronization element for synchronizing the receiver with the nominal predetermined timing of the data packet time slots;
• a window determination element coupled to the first synchronization element for determining, from the nominal predetermined timing and an expected range of transmission delays, a plurality of time windows during which transmitted data packets can be received at the receiver;
• a receiver element coupled to the window determination element for receiving and demodulating the transmitted signal received during each of the plurality of time windows;
• a memory element coupled to the receiver element for storing data derived from the transmitted signal;
• a processor coupled to the memory element for searching a predetermined portion of the data stored during each of the plurality of time windows to locate a point of maximum correlation between the data and a data template matching the sync word;
• a decoder coupled to the processor for decoding the data packet throughout a data packet time slot by utilizing the point of maximum correlation as a reference;
• an error detector coupled to the decoder for examining the error-detecting code word of the data packet decoded to determine whether the data packet is errored;
• and
• a validity definer coupled to the error detector for defining the data packet decoded to be a valid data packet if the data packet is not errored and to be an invalid data packet if the data packet is errored.

A receiver for minimizing false detection of packet data due to noise in a communication system utilizing data packet time slots that have a nominal predetermined timing for receipt, wherein some of the time slots contain a transmitted signal comprising a data packet, while others of the time slots contain only noise, and wherein the data packet comprises a sync word and an error-detecting code word, the receiver comprising:

• an antenna for intercepting the transmitted signal;
• a first synchronization element for synchronizing the receiver with the nominal predetermined timing of the data packet time slots;
• a window determination element coupled to the first synchronization element for determining, from the nominal predetermined timing and an expected range of transmission delays, a plurality of time windows during which transmitted data packets can be received at the receiver;
• a receiver element coupled to the antenna and coupled to the window determination element for receiving and demodulating the transmitted signal received during each of the plurality of time windows;
• a memory element coupled to the receiver element for storing data derived from the transmitted signal;
• a processor coupled to the memory element for searching a predetermined portion of the data stored during each of the plurality of time windows to locate a point of maximum correlation between the data and a data template matching the sync word;
• a decoder coupled to the processor for decoding the data packet throughout a data packet time slot by utilizing the point of maximum correlation as a reference;
• an error detector coupled to the decoder for examining the error-detecting code word of the data packet decoded to determine whether the data packet is errored;
• a validity definer coupled to the error detector for defining the data packet decoded to be a valid data packet if the data packet is not errored and to be an invalid data packet if the data packet is errored;
• a communication interface coupled to the processor for communicating the valid data packet through a communication link;
• and
• a user interface coupled to the processor for allowing a user to monitor and control the receiver.

A communication system for minimizing false detection of packet data due to noise, the communication system comprising:

• at least one first transmitter for generating a transmitted signal comprising a data packet transmitted in at least one of a plurality of data packet time slots that have a nominal predetermined timing for receipt by a first receiver, wherein the data packet comprises a sync word and an error-detecting code word;
• and
• the first receiver coupled by a wireless link to the at least one first transmitter for receiving the transmitted signal, the first receiver comprising:
• an antenna for intercepting the transmitted signal, wherein at least one of the plurality of data packet time slots contains the transmitted signal, while others of the plurality of data packet time slots contain only noise;
• a first synchronization element for synchronizing the first receiver with the nominal predetermined timing of the plurality of data packet time slots;
• a window determination element coupled to the first synchronization element for determining, from the nominal predetermined timing and an expected range of transmission delays, a plurality of time windows during which transmitted data packets can be received at the first receiver;
• a receiver element coupled to the antenna and coupled to the window determination element for receiving and demodulating the transmitted signal received during each of the plurality of time windows;
• a memory element coupled to the receiver element for storing data derived from the transmitted signal;
• a processor coupled to the memory element for searching a predetermined portion of the data stored during each of the plurality of time windows to locate a point of maximum correlation between the data and a data template matching the sync word;
• a decoder coupled to the processor for decoding the data packet throughout a data packet time slot by utilizing the point of maximum correlation as a reference;
• an error detector coupled to the decoder for examining the error-detecting code word of the data packet decoded to determine whether the data packet is errored;
• a validity definer coupled to the error detector for defining the data packet decoded to be a valid data packet if the data packet is not errored and to be an invalid data packet if the data packet is errored;
• a link interface coupled to the processor for communicating the valid data packet through a communication link;
• and
• a user interface coupled to the processor for allowing a user to monitor and control the first receiver.