초록 ▼

Communication systems, including, for example, cell-based mobile communication systems, multiple satellite communication systems, or multibeam satellite systems, require reliable handoff methods between cell-to-cell, beam-to-beam, or satellite-to-satellite respectively. Recent measurement of a CDMA

Communication systems, including, for example, cell-based mobile communication systems, multiple satellite communication systems, or multibeam satellite systems, require reliable handoff methods between cell-to-cell, beam-to-beam, or satellite-to-satellite respectively. Recent measurement of a CDMA cellular system indicates that the system is in handoff about 30% to 50% of an average call period. Therefore, system reliability during handoff is one of the major system performance parameters and eventually becomes a factor in the overall system capacity. The present invention advantageously relates to novel and improved techniques for handoff in cellular communications, multibeam and multisatellite systems. The present invention combines the soft handoff mechanism with a code diversity combining technique (i.e., combining signals from multiple sources), a packet combining technique (i.e., combining multiple signals), and an iterative decoding algorithm (e.g., Turbo Coding).

대표청구항 ▼

[ What is claimed is:] [1.] A mobile communication system, comprising:a source of digital data, for communication to or from a predetermined one of a plurality of mobile stations;a first constituent encoder, coupled to the source, for encoding the digital data into a first code sequence;an interleav

[ What is claimed is:] [1.] A mobile communication system, comprising:a source of digital data, for communication to or from a predetermined one of a plurality of mobile stations;a first constituent encoder, coupled to the source, for encoding the digital data into a first code sequence;an interleaver, coupled to the source, for interleaving the digital data;a second constituent encoder, coupled to the interleaver, for encoding the interleaved digital data into a second code sequence;a first code puncturer, coupled to the first and second constituent encoders, for selectively combining data from the first code sequence and data from the second code sequence according to a first puncturing pattern, to form a first punctured code sequence;a second code puncturer, coupled to the first and second constituent encoders, for selectively combining data from the second code sequence and data from the first code sequence according to a second puncturing pattern, to form a second punctured code sequence;first and second transmitters for transmission of information on first and second logical channels assigned to the predetermined mobile station; andwherein at least during a handoff operation, the first transmitter broadcasts the first channel carrying a first representation of the digital data together with the first punctured code sequence, and concurrently the second transmitter broadcasts the second channel carrying a second representation of the digital data together with the second punctured code sequence.