Abstract: The present invention is related to indexing channel information feedback in a multiple-input multiple-output (MIMO)-based wireless communication system. In one embodiment, at least one measurement of a channel metric is performed. The measured channel metric is quantized and a codeword is selected that represents the measured channel metric. Feedback is generated based on the channel metric measurement. The feedback includes an index to the selected codeword. A codebook is generated by partitioning a plurality of codewords into two or more tiers, assigning indices to the codewords and correlating the codewords in complex vector space and Hamming distance in binary indices. For any given codeword, a first subset of the codewords may have a higher correlation with respect to the given codeword. In another embodiment, the number of bits used to report codebook indexing is determined based on the frequency of the generation of the feedback.
Abstract: Quality requirements on a counter may set a limit to the highest frequency that can be applied to the counter. This will also limit the resolution. A counter is provided including a generator for generating, in response to a first clock frequency, M second clock signals phase shifted with respect to each other and of a second frequency lower than the first frequency, and M secondary counters, each one responsive to a respective one of the M second clock signals for generating a secondary counter signal. The second frequency is adapted to work well in the technology available for realizing the secondary counters, with consideration taken to quality requirements. Furthermore, the counter included a summing circuit responsive to the secondary counter signals for generating the resulting counter signals by adding the secondary counter signals such that the counter signal has the same number of bits and the same significance as the secondary counter signals.
Abstract: A method and apparatus for offering wireless telecommunication service. A switch such as an automatic Private Branch Exchange (PBX), equipped to communicate with Integrated Services Digital Network (ISDN) stations sends ISDN signaling messages to and receives ISDN signaling messages from a protocol converter. The protocol converter, which also communicates with a wireless cell site, converts messages between the ISDN protocol and a protocol for communicating with the wireless cell site. The cell site sets up wireless connections to a mobile station, essentially in its prior art mode, and the PBX sets up connections to the cell site essentially in its prior art ISDN station control mode. The PBX is connected to a class 5 (central office) telecommunications switching system for establishing connections between the public switched telephone network and the PBX, or between outlets of the PBX for a call between wireless stations.
October 3, 1994
Date of Patent:
August 5, 1997
Lucent Technologies Inc.
William Keith Cline, James Joseph Fuentes
Abstract: An electronic step-by-step switching system utilizes much of the equipment now present in conventional electromechanical step-by-step telephone exchange switches. Conventional line finders, selectors and connectors are modified by removing the relay logic and replacing it with microprocessor based controllers. The modified line finders communicate through a bus with an originating controller and the modified connectors communicate through a bus to a terminating controller. The controllers are interconnected for data exchange through high speed buses that are supervised by a bus controller. A programmer station is installed for bi-directional communication through the bus controller. The originating and terminating controllers include memory storage for maintaining status information concerning the subscriber lines within the groups of corresponding line finders and connectors. The modified line finder works in conjunction with the originating controller to identify the line for an off-hook subscriber.
October 31, 1985
Date of Patent:
November 10, 1987
Walter L. Barbare, Harley M. Willey, Ronald D. Higgins
Abstract: An improved step-by-step switch assembly includes an electronic controller conversion module. A programmed microprocessor responds to incoming pulse trains of widely variant make and break ratios and generates precisely timed and shaped pulses to operate vertical, rotary and release magnets of the switch assembly. Other features include increased loop sensitivity, selective digit absorption and automatic periodic contact wiping to clean all of the contacts of the assembly.