Nokia Mobile Phones Limited

Nokia Corporation

John W Noneman

Zhi-Chun Honkasalo

Sona Kapadia

Pasi Liimatainen

Adam F Gould

James R Robertson

John R Gelm

Ari T Hottinen

Sanguoon Chung

Mika Laukkanen

Rodolfo Vadillo

Jussi Kahtava

In a packet data transmission and reception system, a media access control (MAC) message is broadcast by a base station to a plurality of mobile stations. The MAC message contains packet data transmission scheduling information which allows the base station to preemptively control mobile station access to traffic channels in order to maximize the efficiency of packet data transmissions and allow scheduling consideration including priority access, quality of service and maximum bytes per transfer. The MAC message consists of a control frame structure, which comprises scheduling parameters including MAC IDs fields, activity fields, and a field representing the number of free traffic channels in a cell. These parameters enable multiple mobile stations to share, in a time multiplexed fashion, traffic channels for packet data transmission on CDMA based mobile communication systems.

Method for scheduling packet data transmission

Increased data rate transmission in the reverse traffic channel is obtained by modifying a core reverse CDMA traffic channel signal generator and modulator by creating a plurality of parallel pathways, each of which includes a Walsh modulator and a modulo-2 adder which direct-sequence spreads the modulated data using one of a plurality of modified long codes. The DS-spread data signals from each of the parallel pathways are summed and split to the I and Q channels for PN code spreading. The long code variations are obtained by varying one or more bits of the IS-95 standard public long code mask or private long code mask, specifically, one or more bits of the most significant bit (MSB) string of the public long code mask (bits M through M ). Generally, each variable bit provides two possible code channels&mdash;one Fundamental Code Channel and 2 &minus;1 Supplemental Code Channels, where b is the number of bits that can be varied within the long code mask. In another embodiment, a multiplexer may be inserted into a core reverse channel sequence prior the PN spreading function to provide dual channel OQPSK that is consistent with existing IS-95 single channel OQPSK. Different levels of service can be selected using different codes and a plurality of multiplexers located in the error detection and encoding front end of the core reverse channel process sequence.

DS/CDMA reverse link structure for high data rate transmission

In a packet data transmission and reception system a media access control (MAC) message is broadcast by a base station to a plurality of mobile stations. The MAC message contains packet data transmission scheduling information which allows the base station to preemptively control mobile station access to traffic channels in order to maximize the efficiency of packet data transmissions and allow scheduling consideration including priority access, quality of service and maximum bytes per transfer. The MAC message consists of a control frame structure which comprises scheduling parameters including MAC IDs fields, activity fields, and a field representing the number of free traffic channels in a cell. These parameters enable multiple mobile stations to share, in a time multiplexed fashion, traffic channels for packet data transmission on CDMA based mobile communication systems.

A method and apparatus for varying the data transmission rate of a code division multiple access (CDMA) telecommunications system. The method and apparatus may be implemented into an existing system operating according to a standard designed for a base data transmission while utilizing the Walsh modulator length, the data transmission frame structure, the channel encoding scheme, or the I/Q modulation level of the existing system. Serial data is input to a transmitter/modulator at a data rate which is higher than the base data transmission rate. The serial data is received over a time period having a duration equal to the duration of the transmission frame and demultiplexed into a plurality of sets of input data. Each of the plurality of sets of input data is then processed in one of a plurality of subchannels using the system channel encoding and interleaving scheme to generate a plurality of sets of processed data. A output serial data stream is then generated by multiplexing the plurality of sets of processed data from the subchannels together. The serial output stream is generated so that the originally received serial data included in the serial output data stream, is generated at the first data rate. The serial output data stream is spread to generate at least one spread data stream and is then transmitted on the channel during a second time period having a duration equal to the duration of the transmission frame, so that the serial data included in the at least one spread data stream is transmitted at the first data rate.

Cellular CDMA data link utilizing multiplexed channels for data rate

Multicast transmission for DS-CDMA cellular communication wherein a mobile station requests a multicast service by use of a service option and a base station transmits to the mobile station a long code mask and code channel needed to receive the multicast service. No reverse channel is used so that an unlimited number of terminals may receive the multicast service.

Multicast transmission for DS-CDMA cellular telephones

A method and means of modifying the multi-rate high speed data CDMA system by increasing the physical layer data rate to n times the basic IS-95 rate, while not increasing the frame size proportionally to avoid the use of larger frames, and varying the data rate by changing the number of frames, N, transmitted during each period of T sec, using the relationship R=N.times.F/T, where R bps is the physical layer data rate, F bits is the physical layer frame size, and T sec is the frame period and the interleave depth. Using this approach, the data rate can be varied between F/T bps and N.times.F/T bps using the same set of allowed frame sizes. Further, a major frame of data is formed using a fixed number of minor frames in combination, which minor frames are full rate and simple fractions of a full rate, i.e., 1/2 rate, 1/4 rate, and 1/8 rate. A basic data rate is established which is the data rate that will use a single full rate frame. The sizes of the minor frames needed to generate a major frame are determined by dividing the desired data rate by the basic data rate to form a ratio, the integer portion of which ratio indicates the number of full rate frames and the fractional portion of which determines the size of the single fractional rate frame to use. The full rate frames are concatenated with the single fractional rate frame to produce the final frame structure that is transmitted.

Framing technique for a multi-rate CDMA communication system

In a packet data transmission and reception system two inactivity time intervals are used along with a variable data rate including an idle rate, a default or intermediate rate, and a peak rate. When no packet data is available the data rate is reduced to an idle rate to free most of the system capacity used for communicating the packet transmissions. The packet data service connection is thus maintained and the idle rate transmission of idle packets allows the receiving end of the channel to stay synchronized with the transmitter. If the packet data transmission resumes before the first inactivity timer expires the transmission rate returns immediately to the peak rate. However, if the inactivity continues until the first inactivity timer expires, the data rate is preferably not immediately returned to the peak rate. The packet data service connection is instead maintained at the idle rate after the first inactivity timer expires. When the second inactivity timer expires the packet data service is released. If packet data becomes available for transmission between the time the first inactivity timer expires and the second inactivity timer expires, the data packets are transmitted at the intermediate rate, which is generally lower than the peak rate. After the transmitting source receives an acknowledgment from the receiving end of the channel, the data rate switches back to the peak rate.

Method and apparatus for packet data transmission

A PN code acquisition system for Code Division Multiple Access (CDMA) Direct Sequence Spread Spectrum (DSSS) systems, with automatic decision threshold, is based on the combination of the Maximum Likelihood (ML) and Serial Search (SS) acquisition approaches. In contrast to the conventional SS acquisition system, the disclosed system adaptively estimates optimal threshold by exploiting the statistics of the signal and noise, and makes an optimal decision based on the threshold. The system estimates the threshold by employing ML estimation and applies the threshold as in SS acquisition and makes a decision by comparing the updated threshold with the current signal strength. Together with post detection verification logic, this approach will increase detection probability and reduce false alarm probability significantly. An optimum system parameter design approach and the advantages of this approach as compared to conventional approaches (ML or SS acquisition) are demonstrated.

Serial search acquisition system with adaptive threshold and optimal

A radiotelephone (10) capable of operation within a CDMA radiotelephone system. The radiotelephone includes a receiver (30) for receiving a paging channel transmission; a system time pseudonoise (PN) generator (18); and despreading circuitry (20, 22, 24 26, 28), having an input coupled to the receiver, for despreading the paging channel transmission received during at least a portion of the assigned slot. The assigned slot is predetermined to have a duration that is three times the duration of a rollover period of the system time pseudonoise (PN) generator (26.667 msec) and four times the duration of one frame (20 msec), or 80 msec. The use of predetermined masks for initializing the PN generators, and in particular a Long Code PN generator (32), is also described.

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Valley Center, CA, United States of America

John W Noneman