Xuewen Zeng

Bio: Xuewen Zeng is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Random access & Communications system. The author has an hindex of 4, co-authored 7 publications receiving 29 citations.

Method for smoothly upgrading digital terrestrial television broadcasting system to be of two-way

Abstract: The invention provides a method for smoothly upgrading a digital terrestrial television broadcasting system to be of two-way, which is used for smoothly upgrading the digital terrestrial television broadcasting system into a two-way radio broadcasting communication convergence system. The method comprises the following steps: first, a radio uplink return channel is added for a physical transmission layer, and a radio broadband return policy of a plurality of modes based on a software radio technology is adopted at a base station side, and is realized by adding a return signal receiving module at the base station side; an uplink return channel added at a terminal side and a downlink channel of the original broadcasting system can use a frequency division duplex (FDD) mode or a time division duplex (TDD) mode, when the FDD is adopted, the return channel can utilize an idle FM (Frequency Modulation)/VHF (Very High Frequency)/UHF (Ultra High Frequency) broadcasting frequency band formed by frequency planning and spatial-temporal difference, an authorization-free frequency band and an idle broadcasting television frequency band formed in an analog/digital conversion period, and is realized by adding a return signal transmitting module at a two-way terminal side; and for a media access control layer, interactive service is converged in a media access control MAC and broadcasting multiplex MUX layer.

Stream-media business transmission platform system based on transmission network

Abstract: The invention is related to transmission network system, specially is related to digital transmission network system combined with protocol network higher than third layer relevant to model of OSI seven layers closely or loosely The invention includes module of media content provider, conversion gateway of digital video broadcast-Internet protocol, content distribution platform, service router, media server, and intelligent broadband gateway as well as super adapter of user network interface in use for dispatching resources of transmission network Through super adapter, the system is connected to transmission network Features are: function of authentication from one point, mechanism for buffering content in three levels, limiting network flow, and network load in certain range to lighten load of network The invention takes full advantage of characters of layered structure of network

Method for detecting random access of wireless communication system

Abstract: The invention discloses a method for detecting random access of a wireless communication system. In the method, firstly, the receiving end of a base station carries out zero-fill extension respectively on a precursor signal sequence received and transmitted by a random access detecting window and foreseen limited-numbered candidate random access preamble sequences so as to extend the two sequences into length which is power of 2; then, converting frequency domain and time domain by using quick Fourier algorithm, multiplying the frequency domain to obtain an extended power delay distribution sequence, and carrying out quick Fourier conversion on the extended power delay distribution sequence to obtain an inverse transformation sequence; and finally, simply processing the inverse transformation sequence to obtain an original time domain correlation value of the signal receiving sequence and the candidate signal sequence, thereby measuring and judging the random access sequence selected by a terminal and the distance of the terminal and base station according to the time domain correlation value. The measuring method disclosed by the invention can be used to greatly reduce the computational complexity, and improve the property of measuring the random access.

Method for enabling digital ground multimedia broadcasting system to be bi-directional

Abstract: The invention provides a method and a system for enabling a digital ground multimedia broadcasting system to be bi-directional The method combines a digital ground broadcasting downlink with a general packet radio service (GPRS) compatible uplink In a channel physical layer, the downlink continues to use a digital ground broadcast transmission mode to increase a wireless uplink, and the uplink utilizes one or a plurality of 200KHz bandwidth frequency channels of an idle ground wireless transmission frequency range and uses a GPRS uplink transmission mode The uplink and the downlink belong to asymmetric frequency division duplex modes Above the physical layer, media access control of broadcast multiplex and bi-directional bandwidth carries out integration design, and broadcasting services, broadband services and signaling data of the downlink carry out time division multiplexing to a downlink transmission channel Through utilization of the 200KHz frequency channel, the method upgrades a one-way digital broadcasting system to an interactive broadcast and broadband access integration system, supports asymmetric bi-directional services of a broadband downlink and a medium-small bandwidth uplink, and is suitable for providing interactive broadcast and wireless broadband integration services to suburbs, villages and middle-sized and small cities in low cost

Method for requesting upstream data service bandwidth

Abstract: The invention discloses a method for requesting upstream data service bandwidth. The method comprises a competition part which comprises the following steps that: a user makes a bandwidth request in a truncated binary mode, wherein if the next frame sending the bandwidth request receives a bandwidth authorization from a base station, the bandwidth competing request is sent successfully, otherwise the bandwidth competing request is collided; the user judges the user load of the current network according to a broadcasting parameter of the base station and enters a truncated binary exponential back off collision solving process when the network is under a low load, otherwise the user freezes the current truncated binary exponential back off process to carry out the collision waiting process; and the user does not send the bandwidth competing request when a collision waiting frame is not zero, otherwise the user recovers the truncated binary exponential back off process. The method also comprises a non-competition part which is performed to judge whether the bandwidth request can be sent through a piggyback request in a bandwidth stealing mode in turn, and if the bandwidth request cannot be sent in the bandwidth stealing mode or a piggyback request mode, the method enters the competition part.

Method and system for low-overhead data transfer

Abstract: A method for low-overhead data transfer. The method includes initiating, by a first application, TCP connection with a second application, establishing, in response to the initiation, the TCP connection between the first application and the second application, providing, by the first application, pre-post buffer information to the second application, where the pre-post buffer information corresponds to a location in a physical memory of the first computer and where the location in physical memory corresponds to a virtual memory address of the first application. The method further comprising transferring data, by the second application, to the first application using the pre-post buffer information, where transferring the data comprises writing the data directly into a location in the physical memory of the first computer.

An Optimization for CAVLC Code Table Lookup Algorithm in H. 264 Decoder

Abstract: The computational complexity of H.264 video coding standard is two or three times higher than that of H.263 and MPEG-4. Especially, the operation of the entropy coding is one of the most time-consuming parts in the decoder. According to the characteristics of two-dimensional code table for CAVLC, a fast algorithm was proposed in H.264 decoder implementation, which enable different strategies to be made respectively based on the Variable Length Codes and the Fixed Length Codes existing in two-dimensional code table for CAVLC. The computer simulation results indicate that the decoding time of the entropy decode algorithm can be decreased by 75.1%-82.7% than the original algorithm in the H.264 reference software.

Hyper text transfer protocol (HTTP)-data-stream-based transmission management framework

Abstract: The invention provides a hyper text transfer protocol (HTTP)-data-stream-based transmission management framework, which reduces the development workload of each service subsystem and brings convenience to the management and monitoring of system managers of each level over service data transmission. The framework is characterized by comprising a data packaging transmission module, a data transmission module, a data processing module and a data transmission monitoring module, wherein the data packaging transmission module, the data transmission module and the data processing module are connected with the data transmission monitoring module, and are sequentially connected; the data packaging transmission module is provided with a transmission task definition interface and a transmission data type definition interface; and the data transmission module is provided with a transmission channel definition interface and a transmission task configuration definition interface.

Method for enabling digital ground multimedia broadcasting system to be bi-directional

Abstract: The invention provides a method and a system for enabling a digital ground multimedia broadcasting system to be bi-directional The method combines a digital ground broadcasting downlink with a general packet radio service (GPRS) compatible uplink In a channel physical layer, the downlink continues to use a digital ground broadcast transmission mode to increase a wireless uplink, and the uplink utilizes one or a plurality of 200KHz bandwidth frequency channels of an idle ground wireless transmission frequency range and uses a GPRS uplink transmission mode The uplink and the downlink belong to asymmetric frequency division duplex modes Above the physical layer, media access control of broadcast multiplex and bi-directional bandwidth carries out integration design, and broadcasting services, broadband services and signaling data of the downlink carry out time division multiplexing to a downlink transmission channel Through utilization of the 200KHz frequency channel, the method upgrades a one-way digital broadcasting system to an interactive broadcast and broadband access integration system, supports asymmetric bi-directional services of a broadband downlink and a medium-small bandwidth uplink, and is suitable for providing interactive broadcast and wireless broadband integration services to suburbs, villages and middle-sized and small cities in low cost