摘要:
In an illustrative embodiment of the present invention, a channel is allocated to carry messages from each of multiple subscriber units to a base station. Selected messages generated by a subscriber unit that would otherwise be transmitted over an assigned reverse link traffic channel are instead encoded and transmitted to the base station over a shared reverse link channel. Preferably, the shared reverse link channel is time-slotted and each subscriber unit transmits information to the base station in an assigned time slot so that the base station receiving the messages can identify from which subscriber unit a message is sent. Certain bits in a time slot of the shared channel as set by a subscriber unit can be used to communicate a particular message to the base station. For instance, a single bit that is transmitted in a time slot can be encoded to transmit a substitute message from one of the multiple subscriber units to a base station, where the setting of the bit itself indicates a message type.
摘要:
A packet data system such as a TCP/IP network transmits packets containing a variety of data types along links in the network. Packets are transmitted in a stream between nodes interconnected by the links, which conform to a transport layer protocol such as TCP, UDP, and RSTP, and include wireless links, which transmit packets using a radio frequency (RF) medium. Typical protocols, however, are usually developed to optimize throughput and minimize data error and loss over wired links, and do not lend themselves well to a wireless link. By examining the data in a packet, performance characteristics such as a port number are determined. The performance characteristics indicate the application type, and therefore, the data type, of the packets carried on the connection. Since certain data types, such as streaming audio and video, are more loss tolerant, determination of the data type is used to compute link control parameters for the wireless link that are optimal to the type of data being transmitted over the link.
摘要:
A network based processing element for processing audio information improves the understanding of speech or music for intended listeners based on an identifier. The processing involves performing a media enhancement function, where a parameter affecting the utilization or performance aspects of the media enhancement function are dependent upon the identifier. A “media enhancement server” (MES) is included, whereby the audio of a telephone call, video call, multimedia program or other stream to be heard by a specific listener is processed using a personalized audio enhancement parameter to enhance the audio signal such that the listener will enjoy a benefit, such as better comprehension of the information, reduced listening effort, and more listening comfort during the call. The personalized parameters are stored and retrieved based upon the identifier, and used within the MES. The audio portion of the call or stream could be speech, music, or a combination.
摘要:
A single, common correlation filter (CF) core is provided in a receiver for recovery of data from received code division multiple access (CDMA) signals. Signals are received over CDMA channels with different data rates, where the received signals include user information such as pilot and data symbols that have been spread according to different despreading rates including tier 1, tier 2 and tier 3 rates, where tier 1 is the smallest despreading rate. The received signal is correlated at the smallest despreading rate in the correlation filter (CF) by time multiplexing delayed versions of the pseudorandom noise (PN) code. The correlated information is then demultiplexed and pilot-aided QPSK demodulated. The demodulated information is summed at the proper integer multiple of the tier 1 rate to achieve tier 2 and tier 3 despreading rates. According to an embodiment, the three strongest multipaths components in terms of the received power are selected in a window or time period for optimal information recovery.
摘要:
A communication system, such as a wireless CDMA system, detects markers with fewer errors by having field units transmit the markers at different power levels (e.g., 9 dB for one marker and 11 dB for another marker). The difference in power levels of the markers allows the base station to identify the request markers using alternative criteria with a low probability of error, where the alternative criteria may include comparing the markers to respective energy level thresholds, monitoring occupancy of time slots, occupancy of mutually exclusive code channels, or combinations thereof. For example, in one particular embodiment, a request marker, which is generally a high priority marker, is transmitted with higher power, which improves the probability of detection and reduces the probability of false detection of the request marker.
摘要:
An antenna apparatus, which can increase capacity in a cellular communication system or Wireless Local Area Network (WLAN), such as an 802.11 network, operates in conjunction with a mobile subscriber unit or client station. At least one antenna element is active and located within multiple passive antenna elements. The passive antenna elements are coupled to selectable impedance components for phase control of re-radiated RF signals. Various techniques for determining the phase of each antenna element are supported to enable the antenna apparatus to direct an antenna beam pattern toward a base station or access point with maximum gain, and, consequently, maximum signal-to-noise ratio. By directionally receiving and transmitting signals, multipath fading is greatly reduced as well as intercell interference.
摘要:
Multiple field units in a CDMA system are synchronized for communication with a base station using shared forward and reverse link channels. In an illustrative embodiment, each field unit is assigned a time slot in a forward link channel to receive messages from the base station. Likewise, each field unit is assigned a time slot on a common reverse link channel for transmitting messages to the base station. Timing alignment and power level control among each of many field units and the base station is achieved by analyzing coded transmissions received at the base station in a corresponding time slot as transmitted by each field unit. The codes may be orthogonal, pseudonoise (PN), or other codes. The power level of forward control channel messages can thus be individually controlled. In this way, minimal resources are deployed to maintain communication and precise synchronization between a base station and each of multiple users, minimizing collisions between field units transmitting in adjacent time slots on the reverse link.
摘要:
A repeater is configured to selectively generate and transmit control message packets between wireless stations on both a transmit side and a receive side of the repeater. The repeater manages and manipulates an end to end protocol of the control message packets in a manner that does not change media access control (MAC) addresses of the end to end protocol so as to achieve a network objective, such as preventing other transmitters from transmitting while the repeater repeats a signal from its receive side to its transmit side. The control message management is applicable to analog signal repeaters as well as digital repeaters, such as symbol to symbol or packet to packet repeaters, in which physical layer control message management is performed.
摘要:
Multiple field units in a CDMA system are synchronized for communication with a base station using shared forward and reverse link channels. In an illustrative embodiment, each field unit is assigned a time slot in a forward link channel to receive messages from the base station. Likewise, each field unit is assigned a time slot on a common reverse link channel for transmitting messages to the base station. Timing alignment and power level control among each of many field units and the base station is achieved by analyzing messages received at the base station in a corresponding time slot as transmitted by each field unit. Thereafter, a message is transmitted from the base station in a corresponding time slot to a particular field unit for adjusting its timing or power level so that future messages transmitted from the field unit are received in the appropriate time slot at the base station at a desired power level. In this way, minimal resources are deployed to maintain communication and precise synchronization between a base station and each of multiple users, minimizing collisions between field units transmitting in adjacent time slots on the reverse link. This method reduces the frequency a field unit must rely on the use of a slotted aloha random access channel according to IS-95.
摘要:
The present invention provides for making code rate adjustments and modulation type adjustments in a pseudonoise (PN) encoded CDMA system. Coding rate adjustments may be made by changing the number of information bits per symbol, or Forward Error Code (FEC) coding rate. A forward error correction (FEC) block size is maintained at a constant amount. Therefore, as the number of information bits per symbol are increased, an integer multiple of bits per epoch is always maintained. The scheme permits for a greater flexibility and selection of effective data rates providing information bit rates ranging from, for example, approximately 50 kilobits per second to over 5 mega bits per second (Mbps) in one preferred embodiment.