A method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system is described. In one embodiment, the method comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.

Ofdma with adaptive subcarrier-cluster configuration and selective loading

A method and apparatus for subcarrier selection for systems is described. In one embodiment, a method for subcarrier for a system employing orthogonal frequency division multiple access (OFDMA) comprises partitioning subcarriers (101) into groups of at least one cluster of subcarriers (102), receiving an indication of a selection by the subscriber of one or more groups (103) in the groups, and allocating at least one cluster in the one or more groups of clusters selected by the subcarrier for use in communication with the subscriber (104, 105).

Multi-carrier communications with group-based subcarrier allocation

Multi-carrier communications with adaptive cluster configuration and switching

An apparatus and process for allocating carriers in a multi-carrier system is described. In one embodiment, the process comprises determining a location (E, D, C, B, A; fig. 6) of a subscriber (520) with respect to a base station (510), selecting carriers from a band of carriers to allocate to the subscriber (520) according to the location of the subscriber with respect to the base station (510), and allocating selected carriers to the subscriber (520).

Method and apparatus for adaptive carrier allocation and power control in multi-carrier communication systems

A few high power tones (1506, 1508) used for synchronization and/or other purposes are transmitted in a FDM system (400) during a period of time into a region, e.g., sector (SECTOR 1-Y) of a cell (Cell 1-N), e.g., a symbol transmission time period. During normal data transmission symbol periods, signals are transmitted using at least 10 tones, e.g., per symbol time. Less than 5 high power signals (1506, 1508) are transmitted in a symbol time with at least 80% the maximum total transmitter power used for transmitting into said region being allocated to the high power signals where the maximum total transmitter power is determined from a period of time which may includes one or more data and/or high power tone (1506, 1508) transmission periods. When the high power tones (1506, 1508) are transmitted at most 20% of transmitter power used for transmitting into the region is available for transmitting other tones with the power normally being distributed among multiple tones. Often some tones, which would be transmitted in a symbol time go unused during transmission of the high power signals (1506, 1508).

Beacon signaling in a wireless system

In a conventional TDMA wireless system, the blocking probability is affected by the worst case interference statistics. Modifying the system to a frequency-hopped CDMA (CDMA-FH) system can change the blocking probability to be determined by average statistics. Hopping patterns can be implemented easily using Latin squares. A system using Latin squares of size n guarantees no users in the same cell share any slots and a user and all users in different cells share only one out of every n slots. Channel coding over hops then suppresses the worst interference. Further improvements may be obtained by allowing users to occupy M out of N slots where M/spl les/N. Centralized and distributed dynamic channel allocation (DCA) algorithms which allow users to have different SIR requirements have been developed to maximize the capacity of the system under a desired blocking probability. >

C.C. Wang

Papers

Dynamic channel resource allocation in frequency hopped wireless communication systems