Patent application number | Description | Published |
20080267278 | RETRANSMISSION OF REORDERED/CODED DATA IN RESPONSE TO PRESUMED RECEIVER DECODING FAILURE - A method having enhanced decoding operations associated with receiving multiple Radio Frequency (RF) Burst(s) is provided. Multiple RF burst(s) are received where the multiple RF Burst(s) include first RF bursts and second RF Burst(s). The second RF bursts may be transmitted in parallel or in response to a decoding error associated with the first RF burst. The received RF burst(s) are equalized and deinterleaved to yield extracted soft samples. Then the first estimated bit sequences and second estimated bit sequences are decoded from the extracted soft samples. A set of possible bit sequences may then be pruned based on based on combined knowledge of the first estimated bit sequence and the second estimated bit sequences. This pruned set may be compared using a sequence detector and the combined first estimated bit sequences and second estimated bit sequences to select a decoded bit sequence. This allows a sequence detector to use a combination of the original decoded data and the reordered decoded data as constraints when applying a turbo code technique to decode the data. The combination of the original coded data and reordered coded data results in a performance enhancement by providing further constraints. | 10-30-2008 |
20080267330 | FEEDBACK OF REINTERLEAVED CORRECTLY DECODED DATA BLOCK TO DECODER FOR USE IN ADDITIONAL CHANNEL DECODING OPERATIONS OF CHANNEL CODED WORD CONTAINING DATA BLOCK - The feedback of reinterleaved correctly decoded data blocks to a decoder is provided for use in channel decoding operations of channel coded word containing data block. Once a properly decoded data block has been determined, feedback of constraints on the estimated bit sequences decoded data characteristics to a turbo decoder assist in additional decoding operations. Estimated bit sequences may be selected from those trellises that pass through the constraint imposed by knowledge of re-interleaving properly decoded data blocks. This allows the decoder to generate solutions having a minimum probability of error that are also confined by the re-interleaved properly decoded data blocks. | 10-30-2008 |
20080274711 | SUCCESSIVE INTERFERENCE CANCELLATION IN CODE DIVISION MULTIPLE ACCESS SYSTEM USING VARIABLE INTERFERER WEIGHTS - A method for successive interference cancellation in code division multiple access (CDMA) systems is provided that uses variable interferer weights. This method allows interfering signals to be cancelled in order to recover a transmitted data signal. This method involves receiving the data signal subject to interference from at least one interfering signal. A first interfering signal is identified. Then an interferer weight coefficient associated with the first interfering signal is generated. This allows the first interfering signal to be cancelled from the received data signal using the interferer weight coefficient. These processes may then be reiterated for other interfering signals. It is then possible to recover the transmitted data signal from the received data signal. | 11-06-2008 |
20090060000 | Acquisition of spreading factors (SFS) of multiple transmitted signals in code division multiple access system - A method for successive interference cancellation in code division multiple access (CDMA) systems is provided that uses variable interferer weights. This method allows interfering signals to be cancelled in order to recover a transmitted data signal. This method involves receiving the data signal subject to interference from at least one interfering signal. A first interfering signal is identified. Then an interferer weight coefficient associated with the first interfering signal is generated based on its signal strength and SF upon acquisition of the SF. This SF may be monitored such that the Interferer weight may be adjusted when the SF changes based on the detected changes. This allows the first interfering signal to be cancelled from the received data signal using the interferer weight coefficient. These processes may then be reiterated for other interfering signals. It is then possible to recover the transmitted data signal from the received data signal. | 03-05-2009 |
20090097532 | FEEDBACK OF DECODED DATA CHARACTERISTICS - A method for successive interference cancellation in code division multiple access (CDMA) systems is provided that uses variable interferer weights. This method allows interfering signals to be cancelled in order to recover a transmitted data signal. This method involves receiving the data signal subject to interference from at least one interfering signal. A first interfering signal is identified. Then an interferer weight coefficient associated with the first interfering signal is generated. This allows the first interfering signal to be cancelled from the received data signal using the interferer weight coefficient. These processes may then be reiterated for other interfering signals. It is then possible to recover the transmitted data signal from the received data signal. | 04-16-2009 |
20090170439 | CHANNEL ESTIMATION METHOD OPERABLE TO CANCEL A DOMINANT DISTURBER SIGNAL FROM A RECEIVED SIGNAL - A processing module produces improved main channel estimate. This process involves initially estimating the channel impulse response. This result is based on and combined with a known sequences such as that provided by training sequences of the midamble within RF bursts. From this combination, it is possible to produce an estimated signal from a convolution of the channel impulse response and midamble. The estimated signal may be cancelled or subtracted from the received signal to produce a clearer image of the disturber signal. A blind data recovery performed upon the disturber signal. The recovered disturber data may be used as a reference for disturber channel estimation in order to produce a disturber channel impulse response. With the estimated disturber channel impulse response and the recovered disturber data, an estimated disturber signal may be reconstructed and subtracted from the received signal. This allows the cancellation of the estimated disturber signal. Without a clear or dominant disturber signal, a better representation of the main channel impulse response may be produced. This results in more accurate processing of the received RF bursts and improved receiver performance. | 07-02-2009 |
20090207899 | Equalizer training method using re-encoded bits and known training sequences - The present invention provides a multi-branch equalizer processing module operable to cancel interference associated with received radio frequency (RF) burst(s). This multi-branch equalizer processing module includes both a first equalizer processing branch and a second equalizer processing branch. The first equalizer processing branch is operable to be trained based upon known training sequences and equalize the received RF burst. This results in soft samples or decisions which in turn may be converted to data bits. The soft samples are processed with a de-interleaver and channel decoder, where the combination is operable to produce a decoded frame of data bits from the soft samples. A re-encoder may re-encode the decoded frame to produce re-encoded or at least partially re-encoded data bits. An interleaver then processes the at least partially re-encoded data bits to produce and at least partially re-encoded burst. The second equalizer processing branch uses the at least partially re-encoded data bits to train linear equalizer(s) within the second equalizer processing branch. A buffer may initially store the received RF burst(s), which are retrieved and equalized by the second equalizer processing branch once the linear equalizer(s) are trained. This results in alternate soft samples or decisions which in turn may be converted to alternate data bits. The alternate soft samples are processed with the de-interleaver and channel decoder, where the combination is operable to produce an alternate decoded frame of data bits from the alternate soft samples. This allows interfering signals to be cancelled and more accurate processing of the received RF bursts to occur. | 08-20-2009 |
20100246634 | Acquisition of spreading factors (SFS) of multiple transmitted signals in code division multiple access system - A method for successive interference cancellation in code division multiple access (CDMA) systems is provided that uses variable interferer weights. This method allows interfering signals to be cancelled in order to recover a transmitted data signal. This method involves receiving the data signal subject to interference from at least one interfering signal. A first interfering signal is identified. Then an interferer weight coefficient associated with the first interfering signal is generated based on its signal strength and SF upon acquisition of the SF. This SF may be monitored such that the Interferer weight may be adjusted when the SF changes based on the detected changes. This allows the first interfering signal to be cancelled from the received data signal using the interferer weight coefficient. These processes may then be reiterated for other interfering signals. It is then possible to recover the transmitted data signal from the received data signal. | 09-30-2010 |
20100246640 | FEEDBACK OF DECODED DATA CHARACTERISTICS - A method for successive interference cancellation in code division multiple access (CDMA) systems is provided that uses variable interferer weights. This method allows interfering signals to be cancelled in order to recover a transmitted data signal. This method involves receiving the data signal subject to interference from at least one interfering signal. A first interfering signal is identified. Then an interferer weight coefficient associated with the first interfering signal is generated. This allows the first interfering signal to be cancelled from the received data signal using the interferer weight coefficient. These processes may then be reiterated for other interfering signals. It is then possible to recover the transmitted data signal from the received data signal. | 09-30-2010 |
20110026576 | Adaptive interference cancellation algorithm using speech mode dependent thresholds - Adaptive interference cancellation algorithm using speech mode dependent thresholds. A method of processing radio frequency (RF) bursts dependent on a speech mode associated with data contained within the RF burst is presented. Different voice modes, full rate, half rate, and adaptive multi-channel rates each may require different signal to noise ratio (SNR) conditions in order to be successfully processed. To improve the equalization, the SNR associated with the burst is estimated. Based on the SNR or other related conditions, a decision can be made as to whether or not an interference cancellation burst process should be implemented. For example, any one or more of SNR of the signal, a measure of colored noise within the signal, an indication whether the signal being noise limited or interference limited, and a channel profile of the signal may indicate the presence of interference requiring the cancellation of such interference. | 02-03-2011 |
20110105039 | Successive interference cancellation in code division multiple access system using variable interferer weights - A method for successive interference cancellation in code division multiple access (CDMA) systems is provided that uses variable interferer weights. This method allows interfering signals to be cancelled in order to recover a transmitted data signal. This method involves receiving the data signal subject to interference from at least one interfering signal. A first interfering signal is identified. Then an interferer weight coefficient associated with the first interfering signal is generated. This allows the first interfering signal to be cancelled from the received data signal using the interferer weight coefficient. These processes may then be reiterated for other interfering signals. It is then possible to recover the transmitted data signal from the received data signal. | 05-05-2011 |