Marvell International Limited

Marvell Semiconductor, Inc.

Dimitrios-Alexandros Toumpakaris

Hui-Ling Lou

Jungwon Lee

Chris Cheng-Chieh Lee

Kok-Wui Cheong

Methods, software, circuits and systems involving a low complexity, tailbiting decoder. In various embodiments, the method relates to concatenating an initial and/or terminal subblock of the serial data block and outputting decoded data from an internal block of the modified data block. The circuitry generally includes a buffer, logic configured to concatenate an initial and/or terminal subblock to the serial data block, and a decoder configured to decode the data block, estimate starting and ending states for the data block, and output an internal portion of the serial data block and the one or more sequences as decoded data. The invention advantageously reduces the complexity of a suboptimal convolutional decoder, ensures smooth transitions at the beginning and end of the serial data block during decoding, and increases the reliability of the starting and ending states, without adding overhead to the transmitted data block.

Methods, algorithms, software, circuits, receivers and systems for decoding convolutional code

Methods and apparatus are provided for receiving a first signal and generating an output signal indicative of radio data system ('RDS') information. A receiver circuit of the invention can include mixer circuitry, lowpass filter circuitry, downsampler circuitry, and decoder circuitry. Advantageously, the receiver circuit can operate entirely within the digital domain, promoting interoperability with digital frequency modulation ('FM') demodulator circuitry.

Digital radio data system receiver methods and apparatus

Systems and techniques for decoding are described. A described technique includes receiving coded bit streams that are differently encoded versions of an original bit stream, the coded bit streams including coded bits that are based on the original bit stream, where the coded bit streams have different encoding rates; identifying, within the coded bit streams, repeated coded bits of a coded bit of the coded bits that has been repeated N times; combining the coded bit streams to produce a combined bit stream by at least combining the repeated coded bits into a combined coded bit; determining, without multiplying by a normalization factor that is based on N, a bit metric for the combined coded bit that is a function of N; and decoding the combined bit stream by at least using the bit metric.

Soft decoding of coded bit-streams

A transmitter can include an encoder configured to encode a data sequence based on a first encoding rate to generate a first encoded bit stream having first bits with at least one first repeated bit and encode the data sequence based on a second, different encoding rate to generate a second encoded bit stream having second bits with at least one second repeated bit, where the first and second encoded bit streams each fully represent the data sequence. A receiver can include circuitry configured to produce identified repeated bits by identifying a repeated bit in the first encoded bit stream and a repeated bit in the second encoded bit stream that correspond to a same bit position, combine the first encoded bit stream and the second encoded bit stream including the identified repeated bits to generate a combined bit stream, and decode the combined bit stream.

A transceiver configured to be implemented in a first device includes transmitter and receiver modules and first and second estimator modules. The receiver module receives a first signal transmitted on a channel from a second device to the first device. The first estimator module estimates a first parameter associated with the first signal or the channel. The second estimator module estimates a carrier frequency offset based on the first parameter. The carrier frequency offset is a difference between a first carrier frequency of the first device, and a second carrier frequency of the second device. The transmitter module adjusts a second parameter based on the carrier frequency offset, and based on the second parameter, transmits a second signal to the second device or the receiver module adjusts a third parameter based on the carrier frequency offset, and based on the third parameter, receives a third signal from the second device.

Transceiver with carrier frequency offset based parameter adjustment

An adaptive receiver comprises a receiver module that receives an orthogonal frequency division multiplexing (OFDM) signal. An operating parameters module monitors at least one operating parameter of the receiver module and generates a select signal based the at least one operating parameter. An estimator module selects between first and second algorithms based on the select signal and selectively estimates a carrier frequency offset (CFO) of the OFDM signal using the one of the first and second algorithms. Alternately, an estimator module adjusts algorithm operating parameters of a first algorithm based on the select signal and selectively estimates a carrier frequency offset (CFO) of the OFDM signal using the selected algorithm operating parameters of the first algorithm.

Adaptive OFDM receiver based on carrier frequency offset

A wireless system may transmit multiple bit streams representing the same information but with the coded bits being transmitted with different repeat transmission factors. The receiver may derive appropriate combining metrics to optimize decoder performance, while eliminating complicated multiplication operations. The receiver may utilize different soft combining metrics for different bit-to-symbols mappings and types of channels, e.g., additive white Gaussian noise (AWGN) and Rayleigh fading channels.

Systems and techniques relating to wireless communications are described. A described technique includes receiving a plurality of symbols, observing a plurality of data samples in adjacent symbols, and calculating an estimate of an integer portion of a carrier frequency offset based on a cyclic shift and a phase shift of the data samples between symbols. Calculating the estimate can include calculating sum values corresponding to respective symbol indices. Each of the sum values can be based on a summation of max values that correspond to respective data subcarrier indices, the max values being based on a maximum of an absolute value of a real component of a base value and an absolute value of an imaginary component of the base value, where the base value is based on at least one of the data samples.

Integer frequency offset estimation in wireless systems

An apparatus includes an estimator that includes a receiver that receives a plurality of frequency-domain symbols. Each symbol includes at least one of a plurality of pilot samples and a plurality of data samples. The estimator also includes a framer that observes the at least one of the plurality of pilot samples and the plurality of data samples in adjacent symbols, and a calculator that calculates an integer carrier frequency offset (CFO) estimate based on a reliability metric based on the at least one of the plurality of pilot samples and the plurality of data samples that are included in the frequency-domain symbols.

Integer frequency offset estimation based on the maximum likelihood principal in OFDM systems

An Orthogonal Frequency Division Multiplexing (OFDM) synchronization module includes a window generator module, a symbol timing estimator module, and a reliability metric calculator. The window generator module generates a sampling window that bounds a plurality of samples of OFDM symbols. The symbol timing estimator module generates an estimated symbol timing from the plurality of samples before a fast Fourier transform operation is performed on the plurality of samples. The reliability metric calculator calculates a reliability metric for the estimated symbol timing based on the estimated symbol timing. The window generator module changes at least one parameter of the sampling window based on the reliability metric.

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Sunnyvale, CA, United States of America

Dimitrios-Alexandros Toumpakaris