Scheduling user transmissions of mobile stations on a reverse link of a spread spectrum cellular system
View Patent ↗The present invention provides a method and an apparatus for wireless communication between a base station and at least two mobile stations in a cellular system. The method comprises sending on a forward link at least one of a first and a second command to the at least two mobile stations that the base station is serving on a reverse link. The method further comprises controlling a transmission in at least one of a first and a second transmission mode of at least one mobile station among the at least two mobile stations on the reverse link based on the at least one of the first and second commands. Each of at least two mobile stations may determine a change of transmission mode between an orthogonal or a non-orthogonal transmission mode on a reverse link based on a message on a forward link. A scheduler at a serving base station may match scheduling or transmission resources to the transmissions on the reverse link. The mobile stations being served may use orthogonal and non-orthogonal transmission modes for the transmissions in a non-overlapping fashion in any combination of time, frequency and spatial domains. By selectively assigning a set of mobile stations to the orthogonal or non-orthogonal modes of transmission, the serving base station may enable fairness across the mobile stations.
1. A method of wireless communication, comprising:
partitioning at least one reverse link resource between orthogonal and non-orthogonal transmissions such that the reverse link resources allocated to the orthogonal and non-orthogonal transmissions are non-overlapping in at least one resource dimension;
scheduling the orthogonal transmissions using dedicated rate control;
scheduling the non-orthogonal transmissions using common rate control; and
wherein partitioning said at least one reverse link resource comprises allocating a first portion of the reverse link resource to at least one first mobile station for orthogonal reverse link transmission to a base station and allocating a second portion of the reverse link resource to at least one second mobile station for non-orthogonal reverse link transmissions to the base station.
2. The method of claim 1 , wherein partitioning said at least one reverse link resource comprises allocating the first portion of the reverse link resource to a plurality of first mobile stations for transmission according to orthogonal frequency division multiplexing and allocating the second portion of the reverse link resource to a plurality of second mobile stations for transmission according to code division multiple access.
3. The method of claim 1 , wherein allocating the first and second portions of the reverse link resource comprises transmitting first and second messages from the base station to said at least one first mobile station and said at least one second mobile station, respectively, indicating allocation of the first and second portions of the reverse link resource.
4. The method of claim 1 , wherein partitioning said at least one reverse link resource comprises partitioning said at least one reverse link resource such that orthogonal and non-orthogonal transmission are non-overlapping in time.
5. The method of claim 1 , wherein partitioning said at least one reverse link resource comprises partitioning said at least one reverse link resource such that orthogonal and non-orthogonal transmission are non-overlapping in frequency.
6. The method of claim 1 , wherein partitioning said at least one reverse link resource comprises partitioning said at least one reverse link resource such that orthogonal and non-orthogonal transmission are non-overlapping in at least one spatial dimension.
7. The method of claim 1 , wherein scheduling the orthogonal transmissions using dedicated rate control comprises transmitting separate rate commands to each mobile station so that each mobile station can determine a transmission rate independently based on the corresponding rate command.
8. The method of claim 1 , wherein scheduling the non-orthogonal transmissions using common rate control comprises transmitting a common rate command to a plurality of mobile stations so that each of the plurality of mobile stations can determine a transmission rate based on the common rate command.
9. The method of claim 1 , comprising receiving scheduled signals from the first and second mobile stations using the allocated first and second resources.