Method and apparatus for detecting messages with unknown signaling characteristic

A method for decoding messages in which at least one signaling characteristic of the messages is not known a priori, the method comprising:

• receiving a sequence for a transmitted message;
• computing a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• selecting a hypothesized message having a best metric value as the transmitted message,
• wherein the metric is a function of:
• (
• α
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• ,
• where
• αsÊs is an estimated energy of a signal component per symbol in the incoming stream,
• αpÊp is an estimated energy of a pilot component per symbol in the incoming stream
• αs{circumflex over (N)}t is an estimated noise variance per symbol in the incoming stream,
• nm is a length of a message corresponding to the transport format under consideration,
• nc is a length of a codeword corresponding to the transport format under consideration, and
• EVD(nc) is an energy computed by a Viterbi decoder for a hypothesized codeword of length nc.

A method for decoding messages in which at least one signaling characteristic of the messages is not known a priori, the method comprising:

• receiving a sequence for a transmitted message;
• computing a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• selecting a hypothesized message having a best metric value as the transmitted message,
• wherein the metric is expressed as:
• metric
• =
• (
• 1
• σ
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• ∑
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• =
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• c
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• y
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• ,
• where
• m is the hypothesized message being evaluated,
• y is the received sequence,
• nm is a length of the hypothesized message being evaluated,
• nc is a length of a codeword corresponding to the hypothesized message being evaluated,
• V is a magnitude of a transmitted sequence corresponding to the received sequence, and
• σ2 is a variance of noise in a channel via which the received sequence was transmitted.

A method for decoding messages in which at least one signaling characteristic of the messages is not known a priori, the method comprising:

• receiving a sequence for a transmitted message;
• computing a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• selecting a hypothesized message having a best metric value as the transmitted message,
• wherein the metric is expressed as:
• metric
• =
• (
• 1
• σ
• 2
• ⁢
• ∑
• i
• =
• 1
• N
• C
• ⁢
• x
• i
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• y
• i
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• -
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• N
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• RV
• 2
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• 2
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• m
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• ln
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• 2
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• ,
• where
• m is the hypothesized message being evaluated,
• y is the received sequence,
• nm is a length of the hypothesized message being evaluated,
• Nc is a length of a codeword corresponding to the hypothesized message being evaluated,
• √{square root over (RV)}is a magnitude of a transmitted sequence corresponding to the received sequence, and
• σ2 is a variance of noise in a channel via which the received sequence was transmitted.

A method for decoding messages in which at least one signaling characteristic of the messages is not known a priori, the method comprising:

• receiving a sequence for a transmitted message;
• computing a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• selecting a hypothesized message having a best metric value as the transmitted message,
• wherein the metric is expressed as:
• metric=f1(EVD)−f2(Ec)−f3(nm),
• where
• EVD is an energy related to a correlation between the received sequence and a sequence generated by re-encoding the hypothesized message being evaluated,
• Ec is an energy related to a transmitted sequence corresponding to the received sequence,
• nm is a length of the hypothesized message being evaluated, and f1( ), f2( ), and f3( )represent functions of an argument within the parenthesis.

A method for decoding messages in which at least one signaling characteristic of the messages is not known a priori, the method comprising:

• processing input samples to provide pilot symbols,
• processing the input samples to provide data symbols,
• coherently demodulating the data symbols with the pilot symbols to provide received sequence of symbols for a transmitted message;
• computing a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• selecting a hypothesized message having a best metric value as a the transmitted message.

A method for decoding messages in which at least one signaling characteristic of the messages is not known a priori, the method comprising:

• receiving a sequence for a transmitted message;
• estimating signal amplitude of symbols in the received sequence;
• estimating noise variance in the received sequence;
• computing a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• selecting a hypothesized message having a best metric value as the transmitted message.

A receiver unit in a wireless communication system, comprising:

• a demodulator configured to receive and process input samples to derive a received sequence of symbols, and to further derive and provide a plurality of hypothesized sequences based on the received sequence and corresponding to a plurality of hypotheses for at least one unknown signaling characteristic of a transmitted message being recovered from the received sequence;
• a decoder coupled to the demodulator and configured to decode each hypothesized sequence to provide a corresponding decoded message;
• and
• a metric calculator operatively coupled to the demodulator and decoder and configured to compute a metric value for each hypothesized sequence, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized sequences, and to further select a decoded message associated with a best metric value as the transmitted message,
• wherein the demodulator includes:
• a pilot processor configured to receive and process the input samples to provide pilot symbols,
• a data processor configured to receive and process the input samples to provide data symbols, and
• a coherent demodulator coupled to the pilot and data processors and configured to coherently demodulate the data symbols with the pilot symbols to provide the received sequence of symbols.

A receiver unit in a wireless communication system, comprising:

• a demodulator configured to receive and process input samples to derive a received sequence of symbols, and to further derive and provide a plurality of hypothesized sequences based on the received sequence and corresponding to a plurality of hypotheses for at least one unknown signaling characteristic of a transmitted message being recovered from the received sequence;
• a decoder coupled to the demodulator and configured to decode each hypothesized sequence to provide a corresponding decoded message;
• and
• a metric calculator operatively coupled to the demodulator and decoder and configured to compute a metric value for each hypothesized sequence, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized sequences, and to further select a decoded message associated with a best metric value as the transmitted message,
• further comprising:
• a signal and noise estimator coupled to the demodulator and configured to estimate signal amplitude of symbols in a transmitted sequence corresponding to the received sequence and to further estimate noise variance in the received sequence.

An apparatus for decoding messages in which at least one signaling characteristic of the messages is not known a priori, comprising:

• a processor adapted to process input samples to provide pilot symbols,
• a processor adapted to process the input samples to provide data symbols,
• a demodulator adapted to coherently demodulate the data symbols with the pilot symbols to provide received sequence of symbols for a transmitted message;
• a metric calculator adapted to compute a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• a processor adapted to select a hypothesized message having a best metric value as a the transmitted message.

An apparatus for decoding messages in which at least one signaling characteristic of the messages is not known a priori, comprising:

• means for processing input samples to provide pilot symbols,
• means for processing the input samples to provide data symbols,
• means for coherently demodulating the data symbols with the pilot symbols to provide received sequence of symbols for a transmitted message;
• means for computing a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• means for selecting a hypothesized message having a best metric value as a the transmitted message.

A computer program product for decoding messages in which at least one signaling characteristic of the messages is not known a priori, comprising:

• non-transitory computer-readable medium, comprising codes for casing a computer to:
• process input samples to provide pilot symbols,
• process the input samples to provide data symbols,
• coherently demodulate the data symbols with the pilot symbols to provide received sequence of symbols for a transmitted message;
• compute a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• select a hypothesized message having a best metric value as a the transmitted message.

An apparatus for decoding messages in which at least one signaling characteristic of the messages is not known a priori, comprising:

• a receiver that receives a sequence for a transmitted message;
• a signal estimator that estimates signal amplitude of symbols in the received sequence;
• a noise estimator that estimates noise variance in the received sequence;
• a metric calculator that computes a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• a processor that selects a hypothesized message having a best metric value as the transmitted message.

An apparatus for decoding messages in which at least one signaling characteristic of the messages is not known a priori, comprising:

• means for receiving a sequence for a transmitted message;
• means for estimating signal amplitude of symbols in the received sequence;
• means for estimating noise variance in the received sequence;
• means for computing a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• means for selecting a hypothesized message having a best metric value as the transmitted message.

A computer program product for decoding messages in which at least one signaling characteristic of the messages is not known a priori, comprising:

• non-transitory computer-readable medium, comprising codes for casing a computer to:
• receive a sequence for a transmitted message;
• estimate signal amplitude of symbols in the received sequence;
• estimate noise variance in the received sequence;
• compute a metric value for each of a plurality of hypothesized messages corresponding to a plurality of hypotheses for the at least one unknown signaling characteristic of the transmitted message, wherein the metric value is computed based on a metric derived to approximately maximize a joint a posteriori probability between the received sequence and the hypothesized messages;
• and
• select a hypothesized message having a best metric value as the transmitted message.