Nortel Networks Corporation

Other

Microsoft Technology Licensing, LLC

Eman A Fituri

Mark Earnshaw

Bassam M Hashem

Hang Zhang

David G Steer

Gamini Senarath

The present invention uses a portion of an orthogonal spreading code space in a CDMA spectrum for uplink from a user element to a base station. By assigning the user elements one or more codes, which are orthogonal to those used to spread data, to use for uplink , the present invention significantly reduces interference between channels, and between the data channels and the channels, while supporting additional capacity. The codes may be individually assigned to user elements or assigned to groups of user elements. Further, different length codes may be assigned to the user elements to support different rates depending on Quality of Service (QoS) requirements.

Orthogonal signaling for CDMA

A multiplexer function maintains a transmission table of all link control frames sent to a physical layer for transmission to a receiver. The transmission table includes a list of frames from various link control entities in the order in which they were multiplexed together to form a stream of frames. At the receiver, when a frame is detected that is in error, the physical layer sends an indication to its associated demultiplexer function, which sets a timer. When the timer expires, the demultiplexer function issues a message, such as a negative acknowledgement message, directly to the sender via the physical layer. The message includes information about the link control frames preceding and following the errant frame. The identified frames may be associated with different link control entities, and are preferably provided in the order in which they were received. The multiplexer function compares the identified frames in the message to the list of frames in the transmission table to identify the errant frame or frames and operates to effect retransmission of the errant frame.

Efficient frame retransmission in a wireless communication environment

The present invention relates to a link control automatic repeat request (ARQ) operation in a wireless communication environment. When a terminal sends an original request for communication resources, the request includes not only payload size, but preferably quality of service parameters associated with the data to be transmitted. During uplink communications, the base station performs the link control based ARQ for lost or corrupt packets. When lost or corrupt packets are identified, a link control entity at the base station determines the appropriate retransmission parameters and contacts the uplink scheduler, if necessary, to obtain the corresponding communication resources for retransmission. The additional communication resources for retransmission are provided in a message, such as a negative acknowledgement message, which is sent to the mobile terminal to trigger retransmission of the lost or corrupted data.

A method and apparatus for assigning a time slotted code division multiple access carrier for wireless reverse link communication between a device and a base station. One or more performance characteristics corresponding to the device are determined. A code division multiple access spreading code is assigned based on the determined performance characteristics. A time slot for communication with the base station is assigned based on the assigned spreading code. According to one aspect, the assigned spreading code corresponds to one of an SCDMA code and an ACDMA code such that a time slot corresponding to an SCDMA code provides a time slot in which all devices are preferably in time-aligned orthogonal communication with the base station. An increase in channel gain and an increase in channel capacity result as compared with a system where time slots support mixed ACDMA and SCDMA codes.

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Nepean, Canada

Eman A Fituri