Nokia Mobile Phones Limited

Zhi Chun Honkasalo

Harri A Jokinen

Jari Hamalainen

Arto Karppanen

Seppo E Lamberg

Wang Ling

The invention relates to a system for transmitting packet data in the air interface of a digital cellular system based on TDMA, Time Division Multiple Access. The mobile terminated logical channels comprise information channels designated for transmitting information and control channels, which can be a fast paging (FP) channel and an acknowledgement (A) channel. The mobile originated logical channels comprise information channels designated for transmitting information and a reservation (R) channel, whereon the mobile station requests the system to reserve a connection for transmitting packet data. According to the invention, for the TDMA frames there is allocated a variable number of time slots for packet transmission, taking into account the symmetricity/asymmetricity of the packet transmission, as well as the total packet transmission demand of the cell. For fast paging (FP), acknowledgement (A) and reservation (R), there can be employed any of the time slots in the frame allocated for packet transmission. It is advantageous that in each time slot, the subscriber's data is subjected to the same interleaving and forward error coding algorithm, so that the respective time slots of consecutive frames form independent logical sub-channels, which are then reserved for one subscriber according to the needs, and to which the subscriber's data is multiplexed at the beginning of the transmission, and wherefrom it is again demultiplexed after the transmission.

System for transmitting packet data in digital cellular time division multiple access (TDMA) air interface

The invention relates to a method for transmitting packet data in a cellular system. The number of time slots in a TDMA frame dedicated for packet transmission varies according to transmission needs and each logical channel consisting of corresponding time slots in consecutive TDMA frames is independent of the other logical channels. A data packet is encoded in an information channel frame consisting of N-1 information bursts, and between the frames there can be an acknowledge/retransmission request burst (ARQ) reporting that a received frame was error-free or requesting retransmission. Thus, the information channel consists of repeated sequences of N bursts. Also disclosed are the structure of a packet paging burst (PP), packet random access burst (PRA), packet access grant burst (PAG), acknowledge/retransmission request burst (ARQ) as well as the use of the bursts in starting and maintaining the transmission.

System for transmitting packet data in radio telephone TDMA systems

System for transmitting packet data in digital cellular time division

A method is disclosed of demodulating a signal (20) modulated by differential quadrature phase shift keying so that two bits of information are coded into each symbol period. The method comprises using a high frequency clock to determine the time taken (t.sub.1, t.sub.2, t.sub.3, t.sub.4), for the modulated signal to execute a predetermined number of cycles, such as 21, in the symbol period (T) and comparing the time thereby determined with the time (t.sub.o) of execution of the predetermined number of cycles for an unmodulated signal.

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Vantaa, Finland

Zhi Chun Honkasalo