摘要:
A wireless communication system base station includes a number of channel unit boards, each including multiple channel elements for providing processing operations for signals assigned to multiple carriers of the system. A given channel unit board includes a multiplexer which is operative to implement multi-carrier/multi-sector channel pooling by assigning a given one of the channel elements of that board to any one of the multiple carriers of the system. For example, the multiplexer in the given channel board may be operative to connect the channel elements of that board to I/Q signal buses associated with different system carriers. The I/Q signal bus for each of the carriers is then combined on the given board with corresponding signals from other boards. The invention allows each of N channel elements of the given channel unit board to be assigned to a particular one of up to N carriers of the system, thereby providing substantially improved flexibility in terms of system configuration.
摘要:
A wideband code division multiple access (CDMA) communication system overlayed on an IS-95 network generates two or more digital bit streams from a group of wideband digital data streams, each digital bit stream spread to form a CDMA component signal. Each CDMA component signal is combined with a corresponding IS-95 digital bit stream to form a composite CDMA signal, allowing a base station to share transmitter subsystems between the wideband and IS-95 systems. For up to three carrier frequencies, up to three composite CDMA signals are employed. A digital bit stream for a group of summed user conversations in the IS-95 system modulates a respective RF carrier frequency to generate a low-power RF signal. The CDMA component signals of the wideband CDMA system are generated so each has a chip rate identical to the chip rate of the digital bit streams of the IS-95 system. The baseband digital data streams for all wideband user conversations are summed digitally for each targeted RF carrier frequency to produce the composite wideband digital signal for each targeted frequency. In one application, each composite wideband digital signal, each at the IS-95 chip rate, is then used to modulate a carrier frequency which is either the same, or has approximately the same frequency and phase as the carrier frequency used in the IS-95 system. Three low-power RF signals are produced in the wideband system, each having the same spectral characteristics as the corresponding low-power RF signals generated in the IS-95 system. These low-power RF signals at the same frequency are combined into a single signal provided to the amplifier and antenna subsystem of a base station transmitter. In another application, each composite digital signal is digitally combined with a respective IS-95 digital bit stream prior to modulation by respective RF carrier. Therefore, signal combining between the IS-95 and wideband CDMA portions of a base station system is accomplished either digitally or with RF signals prior to amplification, thereby allowing the IS-95 system and wideband CDMA system portions of the base station to share RF filters, amplifiers and antennas of the base station transmitters.
摘要:
A single base station supports the non-diversity transmission of a first digital signal type and the diversity transmission of a second digital signal type. The base station includes primary channel boards for modulating and encoding a first digital signal type and secondary channel boards for modulating and encoding a second digital signal type. A first group of transmit radio modules accept the first digital signal type and the second digital signal type and provides a composite electromagnetic output signal. Each transmit radio module is associated with a different sector. A second group of transmit radio modules accept the second digital signal type from secondary channel boards and provide a diverse electromagnetic output signal for complementing the composite electromagnetic output signal.
摘要:
The present invention is an apparatus and a method for sharing a communication channel among two or more base stations connected to a base station controller via a common transmission line in a channelized format. The present invention allows each of the base stations to receive data transmitted over a shared communication channel from the base station controller, to determine whether the data transmitted from the base station controller is intended for that base station, and to insert its data into the communication channel without interfering with data transmitted by other base stations over the communication channel. In one embodiment, each of the base stations is configured to bridge onto the transmission facility such that signaling messages being transmitted over a signaling channel may be received by all of the base stations. The signaling messages has associated identifiers for specifying particular base stations to which the signaling messages are intended. In another embodiment, each of the base stations can insert its signaling message into the data stream over the signaling channel without interfering with signaling messages already in the data stream.
摘要:
A reconfigurable base station suitable for supporting multiple wireless communication system standards includes a set of channel unit boards, each providing processing operations for user signals assigned to multiple carriers of the system, a set of a radio boards, each generating a radio frequency (RF) output signal for each of at least a subset of the multiple carriers, and a reconfigurable bus interconnecting the channel unit boards and radio boards. The base stations configured to support a particular wireless system standard, such as IS-95 CDMA, by assigning particular user signals to designated signal lines of the reconfigurable bus. The base station may then be reconfigured to support other CDMA standards, such as, e.g., IS-95C with or without Orthogonal to Transmit Diversity (QTD), Multi-Carrier (MC) cdma2009, or Universal Mobile Telecommunications System, (UMTS) by assigning. other user signals to the signal lines of the reconfigurable bus. The assignment of signal lines may be implemented dynamically under the control of software running on a base station control computer, or by establishing fixed connections between the bus signal lines and appropriate ports of the channel unit and radio boards.
摘要:
A method and system for network terminal clock synchronization includes determining a respective round trip delay time from a master terminal to each slave terminal and offsetting the clock of each slave terminal by an amount proportional to the respective determined round trip delay time such that the master terminal and each of the slave terminals have substantially the same point of reference in time. The method and system further include, in response to a trigger signal, determining a respective offset between the master clock of the master terminal and the clocks of each of the slave terminals and offsetting the clocks of each of the slave terminals by an amount proportional to the determined respective offset to synchronize the clocks of each of the slave terminals to the master clock of the master terminal.
摘要:
A method and system for network terminal clock synchronization includes determining a respective round trip delay time from a master terminal to each slave terminal and offsetting the clock of each slave terminal by an amount proportional to the respective determined round trip delay time such that the master terminal and each of the slave terminals have substantially the same point of reference in time. The method and system further include, in response to a trigger signal, determining a respective offset between the master clock of the master terminal and the clocks of each of the slave terminals and offsetting the clocks of each of the slave terminals by an amount proportional to the determined respective offset to synchronize the clocks of each of the slave terminals to the master clock of the master terminal.
摘要:
A system and method distributes wireless signals to areas remote from a base station by incorporating a backplane fiber card connected to a backplane in a base station and a radio fiber card connected to a radio. The backplane fiber card and the radio fiber card are connected together by one or more fiber links, which carry signals between the two fiber cards. The radio can therefore be placed at any location within the length of the fiber link, remote from the backplane. The backplane fiber card can be plugged into a radio card slot in the backplane. In one embodiment, the fiber cards have connectors that connect to standard backplane and radio structures, allowing the invention to be incorporated in existing systems without any modifications to the radio or the backplane itself.
摘要:
A DPRAM is placed in the RF path before the digital to analog converter, to provide dynamic path gain compensation to the digital signal prior to conversion to an analog signal. The DPRAM stores corrections to the signal to compensate for amplitude losses in the signal arising from heat and non-linearities. The DPRAM has two sets of identical addresses. A logic switch, alternately directs an input signal to one of the two sets of addresses. Pre-calculated signal values which compensate for path gain are stored in one of the two sets of addresses in the DPRAM. The signal input to the DPRAM is directed to the other block. The value of the signal input to the DPRAM will determine the address to which the new value can be found. It is this new value which is actually input to the DAC and from which an analog signal is created. The updated values written to the DPRAM are the signal values with path gain compensation that is independently calculated and applied to the RF signal by a Dynamic Path Gain Compensation Controller (“DPGCC”). The DPGCC may apply any known algorithms to compute the path gain compensation and adjust the signal accordingly. In one advantageous embodiment the DPGCC accounts for thermal losses and non-linearity and takes into consideration overdrive protection constraints.
摘要:
A processor monitors the real time forward link power utilization in a base station, and a controller regulates the real time forward link power utilization in the base station. The processor and controller operate in a feedback configuration to maintain call quality and prevent damage to the base station. The processor determines real time forward link power utilization on a per frame basis by taking samples at a per chip rate within each frame. The forward link power is then obtained by taking the mean of the samples.