Marvell International Limited

Ricky Cheung

Yungping Hsu

Nelson Xu

A decoding unit for decoding a modulated signal includes a summing unit having i) a first input, ii) a second input, and iii) an output. The summing unit is configured to i) receive the modulated signal at the first input, ii) receive a feedback signal at the second input, and iii) output a first waveform based on the modulated signal and the feedback signal. A demodulation unit has a first demodulation pathway and a second demodulation pathway. The demodulation unit is configured to i) select between the first demodulation pathway and the second demodulation pathway, ii) receive and demodulate the modulated signal with the first demodulation pathway, and iii) receive and demodulate the first waveform with the second demodulation pathway. The remodulation unit is configured to selectively i) output a first complex waveform based on the modulated signal, and ii) output a subsymbol waveform of the first waveform.

Decoding method and apparatus

A feedback equalizer includes a summing unit having an output and first input for receiving a modulated signal, which includes a symbol defined by a first number of chips. A subsymbol processor is coupled to the output of the summing unit. The symbol processor is capable of generating a subsymbol waveform upon receipt of a second number of chips of the symbol. The second number is less than the first number. A feedback filter is coupled to a second input of the summing unit and the symbol processing unit to selectively filter the subsymbol waveform from the modulated signal.

A method comprises determining maximum and next-maximum correlation candidates for a symbol of a modulated signal, calculating a scalar relationship between the maximum and next-maximum correlation candidates, deriving signal quality associated with the modulated signal based on the scalar relationship, and altering a characteristic based on the derived signal quality.

Method and apparatus for determining signal quality

A decoder comprises an equalizer that receives a modulated signal comprising a plurality of symbols including a first symbol defined by a first number of chips. A subsymbol processor that generates a subsymbol waveform after receiving a second number of chips of the first symbol and before at least one of receiving, decoding, and deciding the first number of chips of the first symbol. The second number is less than the first number, and wherein the equalizer equalizes the modulated signal using the subsymbol waveform.

The present invention is directed to a method, program product, and apparatus that determines a signal quality associated with a symbol modulated signal based on a scalar relationship based on at least one of a comparison of plural correlation candidates for a symbol in the modulated signal or a comparison of the vector corresponding to a decided symbol against a reference. In accordance with one aspect of the present invention, a method and apparatus are disclosed which involve determining maximum and next-maximum correlation candidates for a symbol perceived in the modulated signal, calculating the scalar relationship between the maximum and next-maximum correlation candidates, and deriving a signal quality associated with the modulated signal based on the scalar relationship. In accordance with another aspect of the present invention, a method and apparatus are disclosed which involve determining a decided symbol for the symbol perceived in the modulated signal, calculating a scalar relationship between a vector corresponding to the decided symbol and a reference, and deriving a signal quality associated with the modulated signal based on the scalar relationship. In accordance with either of these aspects, the derived signal quality can be used to alter one or more receiver characteristics of a receiver used to capture the modulated signal.

Techniques and instrumentalities to improve ISI and ICI cancellation in reception of modulated symbols by selectively decoding subsymbols of such modulated symbol before they can be completely decided or perceived as well as use of decoded symbol/subsymbol information in the feedback equalization process are disclosed. In particular, a decoder and corresponding method are disclosed which includes a feedback equalizer capable of receiving a modulated signal including a symbol defined by a first number of chips, along with a subsymbol processor to generate a subsymbol waveform upon receipt of a second number, less than the first number, of chips of such symbol and provide the subsymbol waveform to the feedback equalizer in order to equalize the modulated signal using the subsymbol waveform. Other disclosed aspects including techniques and instrumentalities for improving reception performance when symbols encoded by different modulation schemes are encountered, as well as feedback equalization for Barker encoded symbols present in the received signal.

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Stanford, CA, United States of America

Ricky Cheung