Abstract: A method of operating a communication system includes communicating a traffic channel information stream with a wireless device using a first air-interface scheme while communicating control channel information with the wireless device using the first air-interface scheme. The control channel information is communicated with the wireless device using the first air-interface scheme is used to handover the wireless device from the first air-interface scheme to a second air-interface scheme. After the handover of the wireless device from the first air-interface scheme to the second air-interface scheme, the traffic channel information stream is communicated with the wireless device using the second air-interface scheme while still communicating control channel information with the wireless device using the first air-interface scheme.

Abstract: Reference signals (a.k.a., pilot signals) are broadcast to aid in at least channel estimation, cell selection, and handover. When a multi-antenna mode (i.e., MIMO) is used data signals on one antenna should not interfere with reference signals on another antenna. Reference signal resource elements (a.k.a., slots) being broadcast from one antenna are multiplied by a first Walsh code and the data (or reference) signal resource elements being broadcast from another antenna are multiplied by second Walsh code in the same family. Multiplication by Walsh codes reduces or eliminates the correlation between the data resource elements on a first antenna and the reference signal resource elements simultaneously broadcast on a second antenna.

Abstract: A wireless communication system serves a first wireless device with a first access node using a frequency band and serves a second wireless device in an adjacent cell with a second access node that uses the same frequency band. The communication of a first resource block is scheduled between the first wireless device and the first access node. The communication of a second resource block between the second wireless device and the second access node is also scheduled. The scheduling of the first resource block and the second resource block correspond in time and frequency. The first resource block is encoded with a first orthogonal code from a family of orthogonal codes. The second resource block is encoded with a second orthogonal code from the family of orthogonal codes. After encoding, the first resource block and the second resource blocks are transmitted using the frequency band.

Abstract: A first cell is selected as a center cell for testing. Downlink transmissions from a one or more surrounding cells are loaded with test load levels. The downlink transmissions, when loaded with test load levels, include a selected amount(s) of the data portions of their transmission frames carrying orthogonal channel noise (OCN). A performance indicator of the center cell is measured/determined while the surrounding cell(s) are transmitting test load levels and while the center cell is communicating user traffic between the center cell and a first plurality of wireless devices. The test load levels of the surrounding cells may also include user traffic in addition to the OCN.