Abstract:
The invention includes various approaches to assigning codes in wireless code division multiple access communication systems. The invention estimates the cross code correlation between codes to base the code assignment. One approach assigns codes having a high cross correlation to users having a low transmission power level. Another approach assigns code groups having a high cross correlation to a same coded composite transport channel. Another approach assigns codes using a cross correlation factor of each code to minimize a system noise rise. Another approach uses transmission or reception diversity to assign bad code groups to users having a different diversity relationship. Another approach uses a diversity factor and a cross code correlation factor to assign codes.
Abstract:
A sequence of codes are provided for potential assignment to a user in a wireless hybrid time division multiple access (TDMA)/code division multiple access (CDMA) communication system. At least one timeslot is selected to support the communication. For each selected timeslot, at least one code is selected. If more than one code is selected, the selected codes are consecutive in the provided codes sequence. For at least one of the selected timeslots, an identifier of a first and last code of the selected consecutive codes is signaled. The user receives the signaled identifier and uses the selected consecutive codes, as identified, to support the communication.
Abstract:
The present invention is a base station which receives a communication signal over an uplink common control channel and measures interference on the uplink common control channel in response to the received signal. A channel quality measuring device included in the base station monitors the channel quality of the uplink common control channel and provides a quality margin for the communication signal. A spreading device, then, transmits the quality margin over a downlink control channel in response to the quality margin.
Abstract:
A wireless communication system which comprises a plurality of base stations and a user equipment. Each base station transmits a common primary synchronization code (PSC) in a primary synchronization channel at a different timing within a system frame, and a midamble code in a broadcast channel. A transmitted power level of the PSC and midamble code are at a common fixed ratio for each base station. The user equipment (UE) is capable of conducting cell search and includes a receiver for receiving said PSCs, a signal power measuring device for measuring the power level of received PSCs and identifying a frame timing of received PSCs which exceed a power threshold, and a processor for analyzing data signals received in the primary synchronization channel associated with the PSC with the highest power level of the received PSCs with a threshold exceeding power level. The processor also synchronizes or maintains synchronization with the base station associated with the highest PSC, the data signals including secondary synchronization codes.
Abstract:
A wireless digital communication system includes a base station in communication with a plurality of user equipment mobile terminals (UEs). The system prioritizes the forwarding of blocks of downlink data to designated ones of the UEs. The system employs adaptive modulation and coding (AM&C) to achieve improved radio resource utilization and provides optimum data rates for user services. Blocks of downlink (DL) data are received by the base station which requests downlink (DL) channel quality measurements only from those mobile terminals (UEs) with pending downlink transmissions. The UEs respond to the request by measuring and reporting DL channel quality to the base station, which then allocates resources such that the UEs will make best use of radio resources. The base station notifies the UEs of the physical channel allocation indicating the modulation/coding rate and allocated slots followed by transmission of blocks of downlink data which are transmitted to the UEs.
Abstract:
Data transmission is optimized in a wireless digital communication system including a base station and a plurality of user equipment mobile terminals (UEs). Adaptive modulation and coding (AM&C) is employed to achieve improved radio resource utilization and provide optimum data rates for user services. Blocks of downlink (DL) data are received by the base station which requests downlink DL channel quality measurements only from those UEs with pending downlink transmissions. The UEs respond to the request by measuring and reporting DL channel quality to the base station, which then allocates resources such that the UEs will make best use of radio resources. The base station notifies the UEs of the physical channel allocation indicating the modulation/coding rate and allocated slots followed by transmission of blocks of downlink data which are transmitted to the UEs.
Abstract:
A user equipment has a transmitter for transmitting an access attempt signal and data packets over a random access channel. The access attempt signal requests a base station to permit the user equipment access to the random access channel. A receiver receives access control signals and access control modification signals transmitted from a base station. A controller is operatively coupled to the receiver and transmitter. The controller determines a wait period based on in part the received access control signals and access control modification signals and delays transmission of a subsequent access attempt signal for the wait period in response to an unsuccessful access attempt to the random access channel.
Abstract:
At least one desired communication signal is received by a receiver. The at least one desired communication signal is transmitted in a wireless format of a cell. A plurality of communication signals are received. Communication signals are selected from the plurality. The selected communication signals include each desired communication signal and at least one communication signal originating from another cell. A channel estimate is produced for each selected communication signal. Data is jointly detected for the selected communication signals.
Abstract:
A wireless code division multiple access communication system is modeled. A plurality of snapshots is provided. Each snapshot has a plurality of user equipments (UEs) and base stations. The locations of the UEs in a snapshot vary between the snapshots. For each snapshot, the UEs are assigned to base stations. Resources are sequentially assigned to each UE or groups of UEs and a transmission power level for each UE is determined. For each sequential assignment, an updated transmission power level for any previously assigned UEs is determined. Dropped, served and not admitted (blocked) UEs in the snapshot are determined. Statistics on the performance of the system are gathered using the determined dropped, served and blocked UEs.
Abstract:
A user equipment (UE) receives a reference signal over a physical reference channel using a reference channel receiver and obtains reference power levels from the reference signal. The interference level is obtained and a path loss is calculated in response to the reference signal. Transmit power is then determined for an allocated uplink control channel based, at least in part, upon said path loss and said interference level.