Abstract: A method (300) and a system (100) for processing an orthogonal frequency division multiplexing (OFDM) signal. At least one portion of an OFDM symbol (125) that exceeds an amplitude limiting threshold can be identified. The identified portion of the OFDM symbol (125) can be filtered to generate a pre-distortion noise (145). The OFDM symbol (125) and the pre-distortion noise (145) can be combined to generate a pre-distorted OFDM symbol (165).

Abstract: Various embodiments to provide cancellation techniques that can be used to address the self-quieter problem are described. For example, a receiver that includes a tone selector and a self-quieter suppressor is provided. The tone selector (202) determines and selects a self-quieter corrupted tone from a frequency domain signal that exhibits a self-quieter. The self-quieter suppressor (203) determines an initial phase, an angular speed and an amplitude estimate for the frequency domain self-quieter. The suppressor then generates a reconstructed frequency domain self-quieter using the initial phase, the angular speed and the amplitude estimate and subtracts the reconstructed frequency domain self-quieter from the corrupted tone to produce a self-quieter suppressed tone to replace the corrupted tone. Such an approach can realize a significant reduction in processing and complexity, as compared to known alternatives, making it an attractive and cost-effective solution for dealing with the self-quieter problem.

Abstract: Estimates of carrier signal power S and interference-noise NI at the output of the equalizer in a wireless communication system is obtained by (i) determining the variance, ?Z2, of the noise at the output of the equalizer dependent upon the equalization matrix, WH and an estimate of the variance ?2 of the noise at the receiving antennas, (ii) determining the interference, ?I2, at the output of the equalizer dependent upon the equalization matrix, WH, a transfer function matrix, H, of transmission paths between transmitting antennas and receiving antennas, and an estimate ?X2 of the variance of the transmitted signals and (iii) determining the power, S, of the carrier signal at the output of the equalizer dependent upon WH, H and ?X2. The estimate of the interference-noise NI is calculated as NI=?I2+?Z2. These values may be used to facilitate adaptation of the wireless communication system.

Abstract: A low-density parity-check (LDPC) decoder (304) has a memory (308), and a processor (306). The processor is programmed to initialize (202) the LDPC decoder, calculate (204) a probability for each check node, calculate (206) a probability for each bit node, calculate soft decisions, update the bit nodes according to the calculated soft decisions, calculate (208) values from the calculated soft decisions, perform (210) a parity check on the calculated values, update (218) log-likelihood ratios (LLRs) if a bit error is detected in the calculated values, update the bit nodes according to the updated LLRs, and repeat the foregoing post initialization steps.

Abstract: Disclosed is a method and communication device for suppressing interference. The method comprises performing, with a turbo decoder (314), at least one turbo decoding attempt (1106) on a received signal (1104). The turbo decoding attempt generates at least one whole word code bit therefrom (1108). The whole word code bit (1108) corresponds to a group of bits comprising a transmitted symbol. The method determines if the whole word code bit (1108) has a confidence level exceeding a given threshold (1110). If the whole word code bit (1108) does have a confidence level exceeding the given threshold, the whole code word bit is selected for use in data symbol recovery (1114).

Abstract: A communication device is provided that is capable of operating in an OFDM or communication system and that provides for cancellation of in-band spurs. The communication device identifies a bin of multiple bins associated with an output of an inverse transformer and comprising a spur and estimates one or more spur phase parameters and a spur amplitude in association with the identified bin. In one embodiment of the present invention, the one or more spur phase parameters includes a spur initial phase and a spur change rate. When the communication device receives a signal from another communication device, the communication device transforms the received signal to produce a multiple parallel output signals that are each associated with a bin of the multiple bins and cancels a spur in an output signal associated with the identified bin based on the estimated one or more spur phase parameters and spur amplitude.

Abstract: An apparatus, method, and computer program product are provided for determining a carrier to interference-noise ratio (CINR) and received signal strength indicator (RSSI) in a wireless communication system. A base station calculates a carrier power (C) of at least one user in the wireless communication system, and a noise interference (NI) for one cell or sector in the wireless communication system. The carrier power (C) is divided by the noise interference (NI) to produce a value representative of the carrier to interference-noise ratio (C/NI). The received signal strength indicator (RSSI) is derived by combining weighted carrier power (C) and noise interference (NI).

Abstract: A wireless transceiver (100) that produces soft decisions for received, block error correction encoded codewords and a confidence indicator signifying a likelihood of errors in the detected data. The wireless transceiver (100) processes block encrypted signals, such as feedback channel messages in a WiMax uplink. Upon receiving a signal, a soft decision is determined for received block encoded codewords. A difference is calculated between a soft decision metric for a most likely detected codeword and a soft decision metric for a next most likely detected codeword. This difference is normalized based upon the total decoder input power received over the received signal (201). The normalized difference is then scaled by a channel dependent factor and is time filtered. The normalized and time filtered confidence indicator output (212) is able to be provided to a wireless network controller to assess the usability of the received data.

Abstract: Methods and systems are disclosed for migrating data between a legacy application data repository and an enterprise database. One exemplary system includes a legacy application data repository, an enterprise database, an export module for exporting data from the repository in an enterprise application compatible format, and a check-in module for updating the enterprise database to reflect the exported data. The exemplary system further includes a check-out module for extracting data from the enterprise database and converting the extracted data to an enterprise application compatible format, and an import module for updating the repository to reflect the checked-out data.

Abstract: A base station receives (201) OFDMA messages from a plurality of end user platforms that share all used tones within at least one OFDMA symbol. By one approach this base station then uses (202) a fixed starting time to select contiguous samples from received aggregate multi-user signals wherein the fixed starting time is offset from a reference time that comprises a time at which the base station expects to be receiving the signals from all end users. In combination with the time offset approach noted above or in lieu thereof the base station can process (204) selected contiguous samples using fast Fourier transform and then provide (205) phase rotation with respect to those processed samples. When applying phase rotation, by one approach a phase rotation can be applied (401) to the aggregate multi-user signal and, in addition, individual phase rotation can be applied (402) as determined on a user-by-user basis.

Abstract: A method for selecting at least one operating parameter of a communication system (100). The method can include determining a receive signal strength indicator (RSSI) for a communication signal (330). An intermediate value (D) for the communication signal can be determined based on, at least in part, a received value (ri) of at least one known datum, a predetermined value (pi) of the known datum and a channel estimate ({tilde over (h)}i). Further, a carrier to interference and noise ratio (CINR) can be estimated based on, at least in part, the RSSI and the intermediate value. The operating parameter can be selected based on, at least in part, the estimated CINR.

Abstract: Arrangements relating to an Orthogonal Frequency Division Multiplexing (OFDM) receiver (200) can include performing at least one Low-Density Parity Check (LDPC) decoding attempt on a received signal (725) and evaluating at least one parity check for each LDPC decoding attempt (735). Failed LDPC decoding attempts can be counted according to the evaluated parity checks (740). The signal can be selectively processed through at least one joint demodulation-decoding loop according to the counting of failed LDPC decoding attempts (745).

Abstract: Method and system for synchronizing a receiver in an Orthogonal Frequency Division Multiplexing (OFDM) system. The method comprises transforming (105) a received signal from the time domain into the frequency domain to produce a transformed signal. The method further comprises rotating (110) each set of ranging tones of the transformed signal in the frequency domain based on a corresponding tone index to produce a set of phase-rotated frequency domain received ranging tones that is equivalent to time domain shifted ranging signals. Each ranging tone is rotated iteratively over a predefined set of delay-values and each delay-value within the predefined set of delay-values ranges from zero to a predetermined time delay. Also, the method comprises computing (115) a detection metric corresponding to each delay-value within the predefined set of delay-values based on the set of phase-rotated frequency domain received ranging tones.

Abstract: A low-density parity-check (LDPC) decoder (304) has a memory (308), and a processor (306). The processor is programmed to initialize (202) the LDPC decoder, calculate (204) a probability for each check node, calculate (206) a probability for each bit node, calculate soft decisions, update the bit nodes according to the calculated soft decisions, calculate (208) values from the calculated soft decisions, perform (210) a parity check on the calculated values, update (218) log-likelihood ratios (LLRs) if a bit error is detected in the calculated values, update the bit nodes according to the updated LLRs, and repeat the foregoing post initialization steps.

Abstract: In the present sampling technique of a transmitted data stream, a data stream is divided (318, 504) into a predefined number of sample streams to provide a plurality of sample streams, and for at least two of these sample streams, a metric value is assessed (324, 514, 516) and compared (328, 518) to provide a selected sample stream that is likely to resemble transmitted tones as represented by the data stream. The selected sample stream is then accordingly provided (330, 520) for output.

Abstract: The invention relates to an error correcting decoder apparatus (100) and method. The decoder apparatus (100) comprises a likelihood estimator (101) which generates a sequence of bit value likelihood estimates, such as log likelihood ratios, for multi bit symbols of a data sequence. The decoder apparatus (100) further comprises a decoder element (103), such as a Maximum A Priori (MAP) or appropriate Soft Output Viterbi decoder. The decoder element (103) generates a decoded data sequence in response to the bit value likelihood estimates. The decoder apparatus (100) also comprises a weighted processor (105) which generates a weighted compensation data sequence from the decoded data sequence. The weighted compensation data is used to modify the sequence of bit value likelihood estimates. The decoding is subsequently repeated using the improved bit value likelihood estimates whereby improved decoding performance is achieved.

Abstract: The invention relates to an error correcting decoder apparatus (100) and method. The decoder apparatus (100) comprises a likelihood estimator (101) which generates a sequence of bit value likelihood estimates, such as log likelihood ratios, for multi bit symbols of a data sequence. The decoder apparatus (100) further comprises a decoder element (103), such as a Maximum A Priori (MAP) or appropriate Soft Output Viterbi decoder. The decoder element (103) generates a decoded data sequence in response to the bit value likelihood estimates. The decoder apparatus (100) also comprises a weighted processor (105) which generates a weighted compensation data sequence from the decoded data sequence. The weighted compensation data is used to modify the sequence of bit value likelihood estimates. The decoding is subsequently repeated using the improved bit value likelihood estimates whereby improved decoding performance is achieved.

Abstract: A decoder that provides partial interference cancellation in a multiple user signal includes a turbo decoder (150) that generates hard decisions of both the information and parity bits of each user signal. A multiple access interference generator (110) inputs the hard decision values along with calculated correlation coefficients between users to iteratively calculate a partial interference correction signal, which is weighted and fed back (160) to the next input of the signal before being input to the turbo decoder (150) so as to minimize the multi-user interference.

Abstract: Methods and systems are disclosed for migrating data between a legacy application data repository and an enterprise database. One exemplary system includes a legacy application data repository, an enterprise database, an export module for exporting data from the repository in an enterprise application compatible format, and a check-in module for updating the enterprise database to reflect the exported data. The exemplary system further includes a check-out module for extracting data from the enterprise database and converting the extracted data to an enterprise application compatible format, and an import module for updating the repository to reflect the checked-out data.

Abstract: The present invention achieves the benefits of the improved joint detector previously disclosed with significantly less computation by, first, moving the backward substitution computation outside the detector's decoding iteration loop and, second, by moving the input buffer inside the iteration loop. The backward substitution computation is performed initially as part of a joint detection equalization stage prior to entering the decode iteration loop. Then with each decode iteration, the present invention generates a correction signal that is subtracted from the present input signal to produce the next input signal. Each correction signal is generated from a series of differences between the decoded symbols of the current iteration and those in the previous iteration. Thus, the present invention achieves the same performance improvement over conventional joint detectors as the improved joint detector previously disclosed but with dramatically less computational requirements.