Ericsson Gmbh

Eric Yi-Pin Wang

Amer A Hassan

Kumar Balachandran

Sandeep Chennakeshu

Havish Koorapaty

Paul Wilkinson Dent

Rajaram Ramesh

Torbjorn Wilson Solve

Larry William Massingill

Stan L Reinhold

A system and method for permitting variable information rates and improved error performance using orthogonal or near-orthogonal codes is disclosed. This is achieved by simultaneously transmitting two or more Walsh code words from a given orthogonal code set and/or by transmitting multiple shorter orthogonal codewords sequentially such that their combined length equals the original codeword. It should be emphasized that the present invention can be used with any orthogonal or near-orthogonal code set.

System and method for coding in a telecommunications environment using orthogonal and near-orthogonal codes

A method and associated circuitry for initiating communication between a network station and a user terminal of a radiotelephonic communication system, such as a satellite-cellular communication system. When communication is to be initiated, a paging signal is transmitted by a network station to the user terminal. When the user terminal detects the paging signal, an acknowledgment signal is generated by the user terminal and encoded to increase the margin of the acknowledgment signal. Upon reception, the acknowledgment signal is correlated using a multiplicity of correlators. An increased margin acknowledgment signal acknowledging reception of the paging signal is transmitted to facilitate communication of the acknowledgment signal back to the network station.

Circuitry and method for improved signal reception acknowledgment in a

The details of an improved correlator and efficient method of correlation are disclosed. The last M received signal samples are compared with all shifts of a given M-bit binary codeword. The correlator adds or subtracts each of the signal samples accordingly, as the corresponding shift of the codeword contains a binary '1' or '0' in that position. The total is output for each new signal sample received, with a shift of one position between the signal samples and the codeword.

Efficient correlation over a sliding window

A synchronization method and apparatus for synchronizing a receiver, such as a radiotelephone operable in a cellular communication system with a transmitter. Synchronization signals are transmitted as parts of a control signal to the receiver. Such synchronization signals are of high margins and also permit synchronization of the radiotelephone responsive to a reduced number of calculations. The time for such synchronization is reduced by use of nonlinear transformation metrics, such as logarithmic metrics, which reduce the impact of a noise or error component within the control signal.

Synchronization method, and associated circuitry, for improved

A method for transmitting random access signals from a mobile unit to a satellite or other control station which requires the transmission of less information than in conventional terrestrial cellular or proposed mobile satellite systems. According to the method, the mobile unit acquires synchronization from the satellite and transmits reduced random access information to the satellite, and the satellite calculates time adjustment information for the mobile units based on the reduced random access information. The random access information is reduced by predetermining a slot number for each mobile unit, and by transmitting only the odd or even status of the frame number desired by the mobile unit.

Random access scheme for mobile satellite communications

A synchronization method and apparatus for synchronizing a receiver, such as a radiotelephone operable in a cellular communication system with a transmitter. A synchronization signal is transmitted within a multiframe of a control signal to the receiver, which upon powering up detects an undifferentiated digital bit stream and divides the bits into a succession of discrete portions or bins. Energy accumulations within each such portion are calculated, and a space-profile metric of those portions falling within a synchronization burst pattern computed. Space-profile metrics of adjacent portions are also computed. Taking the differences between a given portion and portions prior to and after the given portion, a difference metric is utilized to better predict the occurrence of a multiframe boundary, facilitating synchronization, despite the presence of other high-power bursts within the transmission.

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Cary, NC, United States of America

Eric Yi-Pin Wang