Abstract: Methods and apparatuses for encoding and decoding a multi-channel audio signal are provided. In the encoding method, spatial information is calculated based on a multi-channel audio signal and a down-mix signal, and a compensation parameter that compensates for the down-mix signal is calculated based on the multi-channel audio signal and the down-mix signal. Thereafter, a bitstream is generated by encoding the spatial information, the compensation parameter, and the down-mix signal and combining the results of the encoding. Therefore, it is possible to prevent deterioration of the quality of sound regarding a multi-channel audio signal by compensating for the multi-channel audio signal using a compensation parameter that compensates for a down-mix signal.

Abstract: We have disclosed an enhanced radio system that provides for the capture and playback of one or more radio stations. The user may tune to a station, or scan through stations, rewind to hear what was missed, and fast-forward through undesired content. The system allows a user to rate content, and to be notified when that content is being played on any station. The system may make radio station recommendations. The system allows the user to respond easily to radio content, download audio content, and send radio content to another user. The system may provide other radio related and radio content related information. The system may provide a karaoke mode. The system may also allow the user to integrate a telephone with the radio. The system may report usage information to a collection facility.

Abstract: Systems and methods for enhanced media playback are disclosed. According to one aspect, during media playback, auxiliary (or secondary) media can be integrated with primary media. For example, an electronic device offering media playback can not only play back media item data but can also play back other auxiliary media data. In one implementation, presentation of a media group can involve not only presentation of media items of the media group but also presentation of auxiliary media. Another aspect pertains to how and when auxiliary media data is to be presented (e.g., played) by an electronic device. Another aspect pertains to updating or refreshing auxiliary media data. Still another aspect pertains to restricting presentation of primary media by an electronic device unless auxiliary data is also presented.

Abstract: Provided are an object-based three dimensional (3-D) audio service system using preset audio scenes and a method thereof. The system and the method are suggested for enabling a user to easily and conveniently watch and listen an object based 3-D audio service by eliminating inconvenience that requires a user to control each of object audio signals of sound sources. The system includes: audio input means for inputting an audio signal; preset audio scene generating means for extracting object audio signals from the audio signal inputted through the audio input means and generating more than one of 3-D audio scene information by arranging the extracted object audio signals in a 3-D space and editing features of each object; and encoding means for encoding and multiplexing the audio signal and the 3-D audio scene information for each object audio signal.

Abstract: To control loudness during a junction between different types of broadcast content, such as a junction between programme and commercial or promotional content, representative loudness values for content respectively before (P) and after (C) the junction are received from a playout automation system. A time-varying gain control is applied before and after the junction in order to smooth loudness around the junction. The audio gain is smoothly increased prior to the junction to a gain (P+C)/2 P times higher than the original gain value. Then, the gain is reduced shortly before the junction to a value (P+C)/2 C times lower than the original gain value. After the junction, the gain is returned smoothly to the original value.

Abstract: A multi-channel signal decoding method is provided. A down-mixed signal representative of a multi-channel signal is decoded, and parameters representing characteristic relations between channels of the multi-channel signal are decoded. An additional parameter is estimated by using the decoded parameters, and the decoded down-mixed signal is up-mixed by using the decoded parameters and the estimated parameter so as to decode the multi-channel signal.

Abstract: An encoding method and apparatus and a decoding method and apparatus are provided. The decoding method includes extracting an arbitrary down-mix signal and compensation information necessary for compensating for the arbitrary down-mix signal from the input bitstream, compensating for the arbitrary down-mix signal using the compensation information, and generating a three-dimensional (3D) down-mix signal by performing a 3D rendering operation on the compensated arbitrary down-mix signal. Accordingly, it is possible to efficiently encode multi-channel signals with 3D effects and to adaptively restore and reproduce audio signals with optimum sound quality according to the characteristics of an audio reproduction environment.

Abstract: Provided are an object-based three dimensional (3-D) audio service system using preset audio scenes and a method thereof. The system and the method are suggested for enabling a user to easily and conveniently watch and listen an object based 3-D audio service by eliminating inconvenience that requires a user to control each of object audio signals of sound sources. The system includes: audio input means for inputting an audio signal; preset audio scene generating means for extracting object audio signals from the audio signal inputted through the audio input means and generating more than one of 3-D audio scene information by arranging the extracted object audio signals in a 3-D space and editing features of each object; and encoding means for encoding and multiplexing the audio signal and the 3-D audio scene information for each object audio signal.

Abstract: A front surround sound reproduction system which improves the performance of beam steering by using a speaker array arranged geometrically on two or more planes or on one curved surface, and a signal reproducing method of the system. The audio reproduction apparatus to reproduce a multi-channel audio signal by using a plurality of speakers includes a signal distribution unit to duplicate a multi-channel audio signal and to distribute the duplicated signals as one or more groups of multi-channel signals corresponding to one or more speaker array groups, a steering processing unit to form sound beams with steering angles predetermined in relation to each speaker array group, from the groups of multi-channel signals distributed by the signal distribution unit, and a speaker array unit having one or more speaker array groups to reproduce the sound beams of each group formed by the steering processing unit, in the speaker array group.

Abstract: Provided are an apparatus and method for coding and decoding a multi-object audio signal. The apparatus includes a down-mixer for down-mixing the audio signals into one down-mixed audio signal and extracting supplementary information including header information and spatial cue information for each of the audio signals, a coder for coding the down-mixed audio signal, and a supplementary information coder for generating the supplementary information as a bit stream. The header information includes identification information for each of the audio signals and channel information for the audio signals.

Abstract: A method of processing an audio signal, comprising: receiving a downmix signal, a residual signal and object information; extracting at least one of a background-object signal and a foreground-object signal from the downmix signal using the residual signal; receiving mix information comprising gain control information for the background-object signal; generating a downmix processing information based on the object information and the mix information; and, generating a processed downmix signal comprising a modified background-object signal to which an adjusted gain corresponding to the gain control information is applied, by applying the downmix processing information to the at least one of the background-object signal and the foreground-object signal is disclosed.

Abstract: A data source sends a synchronization signal and information to several data sinks that use the synchronization signal and a specified parameter to determine when to process the information. The data source and data sinks may comprise wireless nodes such as, for example, a wireless audio source that sends multi-channel data to a pair of wireless earpieces. The wireless earpieces use the synchronization signal and a latency interval to determine the appropriate time to output audio based on the audio channels.

Abstract: A wireless audio device may realize power savings when processing multi-channel data, e.g. 2-channel stereo audio data, by splitting the multi-channel block data into separate data blocks for each channel, e.g. Left-channel data block and Right-channel data block, and processing each separate data block independently in the source device to generate respective data packets targeting corresponding sink devices, e.g. a Left earphone and a Right earphone. The source device may then transmit each data packet to a different corresponding sink device, e.g. a Left-channel packet to a Left earphone and a Right-channel packet to a Right earphone. The data packets may also include header information indicative of whether a next packet is intended for a given sink device, enabling sink devices to enter sleep mode when the header information indicates that a next packet is not intended for the given sink device, to save power.

Abstract: Provided are a method and apparatus for transmitting digital multimedia broadcasting data, and a method and apparatus for receiving digital multimedia broadcasting data. A basic audio signal and a multichannel audio signal are encoded to generate a basic audio stream and a multichannel audio stream, and a first data stream describing property and position data of the basic audio stream and a second data stream describing property and position data of the multichannel audio stream are transmitted as independent streams. According to the performance of the receiving apparatus, an audio signal may be decoded by using just the first data stream only or both the first data stream and the second stream.

Abstract: An apparatus and a method for providing a stereo effect when playing an audio file at a portable terminal are provided. The apparatus includes a component extractor for extracting a mono component and stereo components from an audio signal and a gain controller for determining a signal ratio of the stereo components to the mono component and for controlling a stereo gain according to the signal ratio.

Abstract: A receiving apparatus includes: a local oscillator to output first- and second-local-oscillator signals whose phases are orthogonal to each other; a mixer to output first- and second-intermediate-frequency signals; a first filter to allow a component from a desired signal to pass therethrough, and eliminate a component from an image signal having a frequency symmetrical with that of the desired signal, in the first- and second-intermediate-frequency signals; a second filter to allow a component from the image signal to pass therethrough, and eliminate a component from the desired signal, in the first- and second-intermediate-frequency signals; a comparator to compare levels between output signals of the first and second filters; and a control unit to switch a frequency of the first- and second-local-oscillator signals to a difference frequency between a frequency of the desired signal and the intermediate frequency or a sum frequency thereof, according to a comparison result of the comparator.

Abstract: An audio system including a rendering processor for separately rendering a dialogue channel and a center music channel. The audio system may include circuitry for extracting one or both of the dialogue channel or the center music channel from program material that does not include both a dialogue channel and a center music channel. The dialogue channel and the center music channel may be radiated with different radiation patterns.

Abstract: A method and system for providing remote access to multi-channel audio by periodically polling channels of audio produced by, e.g., an application program by calling an Application Programming Interface (API). A method performs the polling to retrieve audio data from multiple channels and to mix the multiple channels into a mixed multichannel audio that is communicated to a remote computing device. The method transmits a sample minimum duration of audio data retrieved from all channels during at polling interval to provide low latency transmission of audio to remotely connected computing devices.

Abstract: A method and apparatus are provided for smoothly blending analog and digital portions of a composite digital audio broadcast signal by using look ahead metrics computed from previously received audio frames to dynamically adjust either stereo separation or bandwidth or both of the digital audio portion of the digital audio broadcast signal to produce an adjusted digital audio portion that is blended with the analog audio portion.

Abstract: An method and apparatus to extract an audio signal having an important spectral component (ISC) and a low bit-rate audio signal coding/decoding method using the method and apparatus to extract the ISC. The method of extracting the ISC includes calculating perceptual importance including an SMR (signal-to-mask ratio) value of transformed spectral audio signals by using a psychoacoustic model, selecting spectral signals having a masking threshold value smaller than that of the spectral audio signals using the SMR value as first ISCs, and extracting a spectral peak from the audio signals selected as the ISCs according to a predetermined weighting factor to select second ISCs. Accordingly, the perceptual important spectral components can be efficiently coded so as to obtain high sound quality at a low bit-rate.

Abstract: A sound processing device includes: a plurality of sound input units; a detecting unit for detecting a frequency component of each sound input to the plurality of sound signal unit, the each sound arriving from a direction approximately perpendicular to a line determined by arrangement positions of two sound input units among the plurality of sound input units; a correction coefficient unit for obtaining a correction coefficient for correcting a level of at least one of the sound signals generated from the input sounds by the two sound input units so as to match the levels of the sound signals with each other based on the sound of the detected frequency component; a correcting unit for correcting the level of at least one of the sound signals using the obtained correction coefficient; and a processing unit for performing a sound process based on the sound signal with the corrected level.

Abstract: When switching from a digital broadcast to a analog broadcast, a broadcast receiver switches to the analog broadcast after adjusting the reproduced frequency band and the degree of left-right separation of the digital broadcast to be equal to the values of the analog broadcast specified from the receiving state of the analog broadcast respectively, and, when switching from the analog broadcast to the digital broadcast, after adjusting the reproduced frequency band and the degree of left-right separation of the digital broadcast to be equal to the specified values of the analog broadcast respectively and then switching to the digital broadcast, adjusts the reproduced frequency band and the degree of left-right separation of the digital broadcast to be equal to values set for the digital broadcast respectively.

Abstract: System and methods are provided configured to reveal differences in content, such as commercial and program content. An input port may be configured to receive a first plurality of bit stream audio channels. A circuit may optionally be configured to enhance artifacting, noise, and/or bit rate errors and may optionally reduce redundant signal information. A signal processor circuit may be configured to transform the first plurality of bit stream audio channels into a frequency domain. A spectrum analysis system may be configured to compare properties of the first plurality of bit stream audio channels to one or more reference signals. An identification circuit may be configured to identify different content types included in the first plurality of bit stream audio channels.

Abstract: An apparatus for processing an audio signal and method thereof are disclosed.

Abstract: An encoding apparatus comprises a frame processor (105) which receives a multi channel audio signal comprising at least a first audio signal from a first microphone (101) and a second audio signal from a second microphone (103). An ITD processor 107 then determines an inter time difference between the first audio signal and the second audio signal and a set of delays (109, 111) generates a compensated multi channel audio signal from the multi channel audio signal by delaying at least one of the first and second audio signals in response to the inter time difference signal. A combiner (113) then generates a mono signal by combining channels of the compensated multi channel audio signal and a mono signal encoder (115) encodes the mono signal. The inter time difference may specifically be determined by an algorithm based on determining cross correlations between the first and second audio signals.

Abstract: Methods and apparatuses provide personalized radio by outputting selected songs from multiple channels from one or more source streams. Users can specify favorite channels for building their personal playlists, or multiple default playlist channels can be provided by genre or other criteria. User like/dislike inputs via the radio receiver generate filter data used to search all channels for matches or block songs from playback. Filter data can also be based on virtual DJ recommendations. Channel searching for matches involves monitoring real-time song and artist labels or other metadata for all channels carried in a separate data channel. Personalization can also be provided by using filter data to select content from a mixed channel comprising content from a selected group of channels. Connectivity options and web interfaces are provided to facilitate transfer and sharing of customization parameters for personalized radio configuration.

Abstract: An information providing system 1 according to an embodiment of the present invention includes an acoustic signal transmitter 10 for transmitting data in the form of sound waves, a portable telephone 20 serving as an acoustic signal receiver (terminal) for receiving the sound waves and reproducing the data, and a server 50 connected through the Internet 40 to the acoustic signal transmitter 10. The acoustic signal transmitter 10 may transmit the data as sound waves in one-way fashion at a timing determined by the acoustic signal transmitter 10 without reliance on transmission control signals or the like received from the acoustic signal receiver 20. The data which is transmitted as sound waves may employ data frame(s) which may contain information for error detection.

Abstract: A hearing assistance system and method for wireless RF audio signal transmission from at least one audio signal source to ear level receivers, wherein a close-to-natural hearing impression is to be achieved. At least one parameter of the RF signal as received from a transmission unit at a respective receiver unit to create left ear RF signal measurement data and right ear RF signal measurement data, respectively. The angular localization of each transmission unit is obtained by comparing, for each transmission unit, the left ear RF signal measurement data and the right ear RF signal measurement data. The audio signals are processed and distributed according to the estimated angular localization of each transmission unit in a manner so that the angular localization impression of the audio signals from each transmission unit as perceived by the user corresponds to the estimated angular localization of the respective transmission unit.

Abstract: Television audio signal encoders include a matrix that sums a left channel audio signal and a right channel audio signal to produce a sum signal. The matrix also subtracts one of the left and right audio signals from the other to produce a difference signal. The encoders also include a configurable infinite impulse response digital filter that selectively uses one or more sets of filter coefficients to filter the difference signal and/or the sum signals. Each selectable set of filter coefficients is associated with a unique filtering application to prepare the difference signal for transmission. Decoders with the matrix are also disclosed.

Abstract: A device for processing parameters representing Head-Related Transfer Functions includes an input stage configured to receive audio signals of sound sources, a determinor configured to receive reference parameters representing Head-Related Transfer Functions and configured to determine, from the audio signals, position information representing positions and/or directions of the sound sources. A processor is configured to process the audio signals; and an influencer is configured to influence the processing of the audio signals based on the position information yielding an influenced output audio signal.

Abstract: A method including: receiving at least a first input audio channel and a second input audio channel; and using an inter-channel prediction model to form at least an inter-channel direction of reception parameter.

Abstract: An apparatus and method for transmitting a plurality of audio objects using a multichannel encoder and a multichannel decoder are provided. The audio object encoder includes a multichannel encoder determination unit to determine a multichannel encoder to be used for encoding of a plurality of audio objects according to the number of the audio objects, an encoding unit to generate an encoded signal by encoding the plurality of audio objects using the determined multichannel encoder, and a multichannel audio object signal generation unit to generating a multichannel audio object signal, by multiplexing sound image localization information of the plurality of audio objects along with the encoded signal.

Abstract: Provided is an audio transmission system for use in environments having multiple televisions. An audio transmitter couples to a television via the television's audio output jack and frequency modulates the audio signal for transmission on a user selected channel. An audio receiver receives the frequency modulated audio signal and extracts the audio signal. The audio receiver may be charged in a charging station.

Abstract: Architecture for playing back personal text-based messages such as email and voicemail over a vehicle-based media system. The user can use a cell phone that registers over a cellular network to an IMS (IP multimedia subsystem) to obtain an associated IP address. The personal messages are then converted into audio signals using a remote text-to-voice (TTV) converter and transmitted to the phone based on the IP address. The phone then transmits the audio signals to the vehicle media system for playback using an unlicensed wireless technology (e.g., Bluetooth, Wi-Fi, etc.). Other alternative embodiments include transmitting converted message directly to the media system, via a satellite channel, converting the messages via a TTV converter on the cell phone, and streaming the converted messages to the phone and/or the media system for playback.

Abstract: The invention relates to sonic steerable antennae and their use to achieve a variety of effects. The invention comprises a method and apparatus for taking an input signal, replicating it a number of times and modifying each of the replicas before routing them to respective output transducers such that a desired sound field is created. This sound field may comprise a directed beam, focus beam or a simulated origin. Further, “anti-sound” may be directed so as to create nulls (quiet spots) in an already existing sound field. The input signal replicas may also be modified in way which changes their amplitude or they may be filtered to provide the desired delaying.

Abstract: There is disclosed a stereo encoding device capable of accurately encoding a stereo signal at a low bit rate and suppressing delay in audio communication. The device performs monaural encoding in its first layer (110). In a second layer (120), a filtering unit (103) generates an LPC (Linear Predictive Coding) coefficient and generates a left channel drive sound source signal. A time region evaluation unit (104) and a frequency region evaluation unit (105) perform signal evaluation and prediction in both of their regions. A residual encoding unit (106) encodes a residual signal. A bit distribution control unit (107) adaptively distributes bits to the time region evaluation unit (104), the frequency region evaluation unit (105), and the residual encoding unit (106) according to a condition of the audio signal.

Abstract: A dynamic surround channel volume control applies a variable gain control to the surround channels of a multi-channel system. Thus the levels of the surround channels are related to the main volume control of the system. This maintains a predictable relationship between the surround channels and the main or front channels.

Abstract: The broadcasting of audio contents by two loudspeakers is controlled by delivering a first audio content to the two loudspeakers and a further processing in which an auxiliary audio content is received. A second audio content is formed by temporally delaying the auxiliary audio content with a delay dependent on the spacing between the loudspeakers and on a distance between a first loudspeaker and a spot located in front of this first loudspeaker. The second audio content is delivered to the first loudspeaker. A third audio content is formed by inverting the auxiliary audio content. The third audio content is then delivered to the second loudspeaker.

Abstract: An apparatus and method for powering headphone electronics over a standard audio signal cable without interfering with the normal audio transmission or playback of transmitted audio signals. A software application resides on a cell/smart phone or other mobile device that combines the nominal audio output of such a mobile device, like music or spoken word, with a high frequency audio signal to produce a dual component signal. The high frequency component is decoded and rectified outside of the mobile device, either in a connector or on the structure of the headphones themselves, to produce a direct current (“DC”) that powers the headphones. The music or other audible signal component transferred over the audio cable is decoded in parallel and sent to the headphone speakers for normal playback. The invention provides an alternative power source to headphone electronics such as active noise cancelling headphones over the audio cable.

Abstract: An apparatus for processing a media signal and method thereof are disclosed, by which the media signal can be converted to a surround signal by using spatial information of the media signal. The present invention provides a method of processing a signal, the method comprising of generating rendering information by using spatial information indicating features between multi-sources and filter information having a surround effect; and generating a surround signal by applying the rendering information to a downmix signal generated by downmixing the multi-sources, wherein a tab number of a filter used in applying the rendering information to generate the surround signal is variable.

Abstract: Systems and techniques for digital processing of FM stereo signals are described. In some implementations, a receiver system is provided. The receiver system can include a received signal input configured to receive a digital signal based on a received mono signal or a received stereo signal. The receiver system can also include a stereo detector coupled with the received signal input, the stereo detector configured to produce a stereo detection signal indicating either a received stereo signal or a received mono signal. The receiver system can further include a digital signal processor coupled with the stereo detector, the digital signal processor configured to process the digital signal based on stereo transmission when the stereo detection signal indicates a received stereo signal and process the digital signal based on mono transmission when the stereo detection signal indicates a received mono signal.

Abstract: Described are computer-based methods and apparatuses, including computer program products, for audio data processing. In some examples, a 3-dimensional audio projection method includes receiving a first set of audio transmissions, each of the audio transmissions in the first set of audio transmissions comprises audio data and location data; determining, for each of the audio transmissions in the first set of audio transmissions, a relative location of the audio transmission based on a location of a receiver and the location data; and projecting, for each of the audio transmissions in the first set of audio transmissions, the audio data to a user in a 3-dimensional format based on the relative location of the audio transmission.

Abstract: An audio decoding method includes: acquiring, from encoded audio data, a reception audio signal and first auxiliary decoded audio information; calculating coefficient information from the first auxiliary decoded audio information; generating a decoded output audio signal based on the coefficient information and the reception audio signal; decoding to result in a decoded audio signal based on the first auxiliary decoded audio signal and the reception audio signal; calculating, from the decoded audio signal, second auxiliary decoded audio information corresponding to the first auxiliary decoded audio information; detecting a distortion caused in a decoding operation of the decoded audio signal by comparing the second auxiliary decoded audio information with the first auxiliary decoded audio information; correcting the coefficient information in response to the detected distortion; and supplying the corrected coefficient information as the coefficient information when generating the decoded output audio signal.

Abstract: There is provided a playback method for decode-processing and playing back coded audio data which is transmitted with necessary stereo process information required for a stereo process intermittently multiplexed into coded information of a monaural audio signal. The playback method includes a first step of outputting stereo audio signals using the monaural audio signal if the necessary stereo process information is not supplied; a second step of starting updating stereo variables within filters, and outputting the stereo audio signals using the monaural audio signal until all the state variables are updated, if the necessary stereo process information is supplied; and a third step of performing the stereo process based on stereo process information acquired by the necessary stereo process information, on the monaural audio signal to generate and output stereo audio signals, if all the state variables within the filters are updated.

Abstract: Provided are an apparatus and method for coding and decoding a multi-object audio signal. The apparatus includes a down-mixer for down-mixing the audio signals into one down-mixed audio signal and extracting supplementary information including header information and spatial cue information for each of the audio signals, a coder for coding the down-mixed audio signal, and a supplementary information coder for generating the supplementary information as a bit stream. The header information includes identification information for each of the audio signals and channel information for the audio signals.

Abstract: A signal recording and reproducing apparatus includes an encoder encoding an input signal to produce a first group of encoded data, and a second group of encoded data used for reproducing a signal of higher quality than a signal resulting from decoding of the first group of encoded data, a recording unit recording record-data, including the first group and the second group of encoded data, into a recording medium, a reproducing unit reproducing the record-data from the recording medium, a decoder decoding at least the first group of encoded data out of the record-data from the reproducing unit, and a controller controlling an operation of each part of the recording and reproducing apparatus, and the controller performs control so as to cause the recording unit to erase the second group of encoded data according to a command to increase the amount of free storage capacity of the recording medium.

Abstract: A method for transmitting, by a mobile device, a data object, is provided, and includes estimating expected transmission times required for transmitting an object between devices by an acoustic communication link and supported radio interfaces, based on a size of the object, transmitting the object through an acoustic communication channel when the link is estimated to provide a shortest expected transmission time, and determining rankings of the radio interfaces according to the expected transmission times when the acoustic communication link does not provide a shortest expected transmission time, transmitting rankings information and configuration information on the supported radio interfaces through the acoustic communication channel by a configuration container, and transmitting the object through a radio interface through which a response is received.

Abstract: An apparatus for processing a media signal and method thereof are disclosed, by which the media signal can be converted to a surround signal by using spatial information of the media signal. The present invention provides a method of processing a signal, the method comprising of extracting a downmix signal from a bitstream; generating a decorrelated downmix signal by applying a decorrelator to the downmix signal; and generating a surround signal by applying rendering information for generating a surround signal to the downmix signal and the decorrelated downmix signal.

Abstract: Audio encoding method and device comprising the transmission, in addition to the data representing a frequency-limited signal, of information relating to a temporal filter that is to be applied to the entire enhanced signal, both in its transmitted low-frequency part and in its reconstituted high-frequency part. The application of this filter for reshaping the reconstituted high-frequency part and the correction of compression artefacts present in the transmitted low-frequency part. In this way, the application of the temporal filter, simple and inexpensive, to all or part of the reconstituted signal, makes it possible to obtain a signal of good perceived quality.

Abstract: Estimates of spectral magnitude and phase are obtained by an estimation process using spectral information from analysis filter banks such as the Modified Discrete Cosine Transform. The estimation process may be implemented by convolution-like operations with impulse responses. Portions of the impulse responses may be selected for use in the convolution-like operations to trade off between computational complexity and estimation accuracy. Mathematical derivations of analytical expressions for filter structures and impulse responses are disclosed.