Abstract: Apparatus and associated methods are provided which allow a remote user to maintain a virtual session with a server. A virtual session allows a remote and possibly mobile user to maintain a virtual presence in an office environment without actually being present. Using the present invention, a remote user can access a central application program such as an Internet service provider, a database system, an inventory system or billing system. Likewise, the remote user can receive calls and other forms of communications as though he or she were present in an office environment. A virtual session does not require a physical connection to be continuously present in order to provide a virtual connectivity. This is especially important for mobile applications where the remote user may incur long distance and/or wireless toll charges.

Abstract: The present invention centers upon uplink communication protocols for use primarily with orthogonal frequency division multiple access (OFDMA) communication systems. Aspects of the invention relate to narrow band frequency division multiplexed (NBFDM) modulation protocols primarily for uplink usage in asymmetric OFDMA communication systems. In particular, NBFDM uplinks that use quadrature multiplexed continuous phase modulation are detailed and noncoherent detection schemes are developed to process the uplink channel signals without the need to transmit uplink phase reference signals. Other aspects of the invention relate to burst mode uplink communications in OFDMA systems such as those involving opportunistic beamforming.

Abstract: Compact pulse shape partial response (CPS PR) signaling is developed for trellis based signals like QM-MSK, and for PAM/QAM type signals to improve the performance to bandwidth tradeoff. Compact pulse shaped signals are partial response signals that employ a very short pulse shaping filter and use Viterbi decoding to optimally detect the CPS signal in presence of its inherent inter-symbol interference. The CPS filters considered herein have much shorter impulse response than the well-known raised cosine (RC) filter. There is no need to equalize the received signal to eliminate ISI or to allow a fixed amount of ISI between received signal samples as sampled at the symbol rate as is common in partial response maximum likelihood (PRML) systems. Numerical results indicate that CPS QM-MSK and CPS QAM provides between several dB of gain, depending on constellation size, over PR-CPM and RC QAM, when compared at a given value of bandwidth, i.e., B99Tb.

Abstract: A geographical web browser allows a user to navigate a network application such as the Word Wide Web by physically navigating in geographical coordinates and roaming through coverage areas of cellular base stations, wireless LANs, microcells, and other such broadcast domains. A mobile unit communicates with a network server via an air interface that supports wireless packet data. Information is transmitted from the network server to the mobile unit based upon the mobile unit's current location. In some embodiments, the information is used to notify the user that further information is available for download.

Abstract: A reduced complexity precoder provides an efficient method and structure to precode a vector-signal-point sequence for transmission through a band-limited channel. The precoder enables a block-oriented receiver to recover an underlying data stream in the presence of inter-symbol interference and noise. The precoder structure is applicable to multicarrier systems such as DMT (discrete multitone) or related transform domain and vector communication systems. The inventive precoder reduces the cost of precoding by an order of magnitude and eliminates the need for a cyclic prefix in DMT and related communication systems. Related multicarrier transmitter and receiver structures and methods which reduce computation, increase transmission bandwidth and reduce transmission power are also developed.

Abstract: Serially-concatenated codes are formed in accordance with the present invention using a constrained interleaver. The constrained interleaver cause the minimum distance of the serial concatenated code to increase above the minimum distance of the inner code alone by adding a constraint that forces some or all of the distance of the outer code onto the serially-concatenated code. This allows the serially-concatenated code to be jointly optimized in terms of both minimum distance and error coefficient to provide significant performance advantages. These performance advantages allow a noise margin target to be achieved using simpler component codes and a much shorter interleaver than was needed when using prior art codes such as Turbo codes. Decoders are also provided. Both encoding and decoding complexity can be lowered, and interleavers can be made much shorter, thereby shortening the block lengths needed in receiver elements such as equalizers and other decision-directed loops.

Abstract: A network scanner, communication protocols, and client and server programs and are provided which provide an improved way to transmit legally binding documents, obviating the need for outmoded, legacy fax transmissions. Using the network scanner, a document may be scanned and transferred directly into any shared folder inbox residing on any computer attached to the Internet. Enhanced server systems and network communications and messaging protocols are provided that are more practical to use than email for sending documents such as executed legal documents or other documents requiring robust integrity and authenticatability. Similarly, the inventive network scanner, server systems and communication protocols provide improved ways to perform large file transfers and to manage bandwidth to minimize problems associated with uploading/downloading large files as attachments to/from email servers and for enabling user control over VoIP quality during file transmission sessions.

Abstract: A first convolutional coder (building-block trellis coder) is used to establish a minimum squared Euclidian distance (MSED) between signal points within a coded constellation building block. A second convolutional encoder (tiling encoder) is designed to ensure that the building block's MSED is maintained between building blocks once they are tiled onto an integer lattice. When this approach is applied to the trellis code of the WiMAX standard, a 3 dB coding is realized. Recall that Wei's 16-state 4D code suffered from a 1.36 dB due to constellation expansion, resulting in a net 4.66 dB coding gain. Our building block approach recovers 1.33 dB of this loss with only a minor increase in coding complexity. We then use the building block approach to derive simpler and more powerful higher dimensional codes that provide further gains still over the Wei family of multidimensional codes.

Abstract: Compact pulse shape partial response (CPS PR) signaling is developed for trellis based signals like QM-MSK, and for PAM/QAM type signals to improve the performance to bandwidth tradeoff. Compact pulse shaped signals are partial response signals that employ a very short pulse shaping filter and use Viterbi decoding to optimally detect the CPS signal in presence of its inherent inter-symbol interference. The CPS filters considered herein have much shorter impulse response than the well-known raised cosine (RC) filter. There is no need to equalize the received signal to eliminate ISI or to allow a fixed amount of ISI between received signal samples as sampled at the symbol rate as is common in partial response maximum likelihood (PRML) systems. Numerical results indicate that CPS QM-MSK and CPS QAM provides between several dB of gain, depending on constellation size, over PR-CPM and RC QAM, when compared at a given value of bandwidth, i.e., B99Tb.

Abstract: Compact pulse shape partial response (CPS PR) signaling is developed for trellis based signals like QM-MSK, and for PAM/QAM type signals to improve the performance to bandwidth tradeoff. Compact pulse shaped signals are partial response signals that employ a very short pulse shaping filter and use Viterbi decoding to optimally detect the CPS signal in presence of its inherent inter-symbol interference. The CPS filters considered herein have much shorter impulse response than the well-known raised cosine (RC) filter. There is no need to equalize the received signal to eliminate ISI or to allow a fixed amount of ISI between received signal samples as sampled at the symbol rate as is common in partial response maximum likelihood (PRML) systems. Numerical results indicate that CPS QM-MSK and CPS QAM provides between several dB of gain, depending on constellation size, over PR-CPM and RC QAM, when compared at a given value of bandwidth, i.e., B99Tb.

Abstract: A smart card is used with a network based system to providing portable telecommunication and computing services. In an exemplary embodiment the smart card holds a user authentication code and user telephony account information. The smart card transfers the user authentication code and the account information to one of a plurality of geographically dispersed card readers which are each connected to a local telephony device. When the smart card is plugged into a first card reader, telephone calls directed to the smart card user's follow-me telephone number are received at a first local telephony device. When the smart card is plugged into a second smart card reader, telephone calls directed to the follow-me telephone number are received at a second telephony local device. Hence the user is enabled to receive and place calls using any of the geographically dispersed telephony devices as though they were his/her own personal landline or cellular telephone supplied by his/her telephony services provider.

Abstract: A smart card is used with a network based system to providing portable telecommunication and computing services. In an exemplary embodiment the smart card holds a user authentication code and user telephony account information. The smart card transfers the user authentication code and the account information to one of a plurality of geographically dispersed card readers which are each connected to a local telephony device. When the smart card is plugged into a first card reader, telephone calls directed to the smart card user's follow-me telephone number are received at a first local telephony device. When the smart card is plugged into a second smart card reader, telephone calls directed to the follow-me telephone number are received at a second telephony local device. Hence the user is enabled to receive and place calls using any of the geographically dispersed telephony devices as though they were his/her own personal landline or cellular telephone supplied by his/her telephony services provider.

Abstract: An family of improved trellis coded signaling schemes is provided that by vary the signal constellation to a smaller constellation periodically according to a pre-selected pattern. A set of specific embodiments involving periodically-reduced 4-PAM/2-PAM trellis coded schemes are disclosed that change their signal constellations periodically from 4-PAM to 2-PAM during selected intervals to improve performance. Similar periodically QAM and higher-dimensional coding schemes are also disclosed. Simplified receiver and decoder structures to decode the periodically-reduced trellis codes are also presented. The present invention allows embodiments to be produced that reduce coding complexity, reduce decoding complexity, and simplify symbol timing recovery and equalization. The cost is a moderate increase in the path memory length of the decoder.

Abstract: Methods, apparatus, and business techniques are disclosed for use in distributed communication systems comprising a plurality of communication protocols. In one embodiment a first air interface is used to initiate communication between a wireless client and a remote server at least partially using a first wireless access point. The server sends the wireless client a stub of a distributed object. The stub is used to instantiate an object class. The object class defines an interface that the remote client can use to communicate with the remote server using an upper layer interface. The distributed object stub also provides an implementation of a software radio configuration for a set of lower protocol layers in a second air interface. The wireless client can thereby communicate with a second wireless access point using said second air interface protocol.

Abstract: A portable VoIP telephony service includes a portable device that includes a processor and memory having information stored therein. If the portable device is coupled to a first computer, information is coupled via the first computer to the telephony service, and in the event a first incoming telephone call is received, the telephony service causes the first incoming call to be directed as a first VoIP call to the first computer. If the portable device is coupled to the second computer, information is coupled via the second computer to the telephony service, and in the event a second incoming telephone call is received while the portable device is coupled to the second computer, the telephone service causes the second incoming telephone call to be directed to the second computer.

Abstract: A class of bandwidth reduction techniques are used develop a broad class of modulation types collectively called SSB-FM. These signals can be used to construct communication systems that provide bandwidth-normalized performance gains of 10 dB or more when compared to popular prior art modulation methods. An aspect of the invention involves mapping trellis paths in a complex signal space onto corresponding real-valued trellis signals with desirable spectral properties. The invention can be used map continuous phase modulated (CPM) signals onto simpler amplitude-modulated trellis signals having double the channel capacity of prior art CPM signals. Multi-amplitude signaling and frequency division multiplexing may also be incorporated to further accommodate more information per symbol.

Abstract: Two decoding algorithms are introduced for the decoding of multi-level coded modulation and other types of coded modulation involving component codes and interleaving operations. An improved hard iterative decoding (IHID) algorithm is presented that improves upon a hard iteration decoding technique by adding a stopping criterion. Also, a list Viterbi hard iteration decoding (LV-IHID) algorithm is presented that employs list decoding in conjunction with the IHID algorithm. Both of these decoding algorithms improve upon conventional multi-stage decoding by reducing the effective error multiplicity that is observed at the lowest coding level. It is demonstrated that the LV-IHID algorithm performs close to soft iterative decoding. The computational and delay complexity of the proposed decoding algorithms compare favorably with soft iterative decoding strategies. Also, a novel labeling strategy for MLC design is presented.

Abstract: Methods, apparatus, and business techniques are disclosed for use in mobile network communication systems. A mobile unit such as a smart phone is preferably equipped with a wireless local area network connection and a wireless wide area network connection. The local area network connection is used to establish a position-dependent ecommerce network connection with a wireless product or service access device supplied by a vendor. A negotiation sequence is carried out to electronically contract the services of the negotiated wireless peripheral from the vendor using a prepaid ecommerce protocol. The negotiated wireless peripheral is a general product or service vending device and the mobile unit acts as a digital authentication and payment device with digital pre-paid payment capabilities. The techniques are useful in many applications to include ticketing and admission systems to events and other types of services that involve ticketing.

Abstract: Methods, apparatus, and business techniques are disclosed for use in distributed communication systems comprising a plurality of communication protocols. In one embodiment a first air interface is used to initiate communication between a wireless client and a remote server at least partially using a first wireless access point. The server sends the wireless client a stub of a distributed object. The stub is used to instantiate an object class. The object class defines an interface that the remote client can use to communicate with the remote server using an upper layer interface. The distributed object stub also provides an implementation of a software radio configuration for a set of lower protocol layers in a second air interface. The wireless client can thereby communicate with a second wireless access point using said second air interface protocol.

Abstract: A network based communication system allows a voice-over-IP (VoIP) packet data connection to be established by sending a subscriber address to a remote database server. The database server converts the subscriber address to an Internet address and informs the wireless handset of an active Internet address to be used to complete the call. In some embodiments the subscriber address is a telephone number that can also be used to reach the subscriber using the public switched telephone network. Other types of media are also supported like digital pictures, digital video, chat sessions, and application sharing sessions.