Techniques to more efficiently transmit pilot and signaling on the uplink in an OFDM system. With subband multiplexing, M usable subbands in the system are partitioned into Q disjoint groups of subbands. Each subband group may be assigned to a different terminal for uplink pilot transmission. Multiple terminals may transmit simultaneously on their assigned subbands. The transmit power for the pilot may be scaled higher to attain the same total pilot energy even though S instead of M subbands are used for pilot transmission by each terminal. Pilot transmissions from the terminals are received, and a channel estimate is derived for each terminal based on the pilot received on the assigned subbands. The channel estimate comprises a response for additional subbands not included in the assigned group. Subband multiplexing may also be used for uplink signaling transmission.

Uplink pilot and signaling transmission in wireless communication systems

Pilot signal transmission sequences and methods are described for use in a multi-sector cell. Pilots in different sectors are transmitted at different known power levels. In adjacent sectors a pilot is transmitted while no pilot is transmitted in the adjoining sector. This represents transmission of a NULL pilot signal. A cell NULL is also supported in which NULL pilots are transmitted in each sector of a cell at the same time. Multiple pilot signal measurements are made. At least two channel quality indicator values are generated from measurements corresponding to at least two pilot signals of different power levels. The two values are transmitted back to the base station which uses both values to determine the transmit power required to achieve a desired SNR at the wireless terminal. The wireless terminal also reports information indicating its location to a sector boundary.

Pilot signals for use in multi-sector cells

Techniques for efficient signaling to and from a plurality of mobile stations are disclosed. In one embodiment, a subset of mobile stations may be allocated a portion of the shared resource with one or more individual access grants, another subset may be allocated a portion of the shared resource with a single common grant, and yet another subset may be allowed to use a portion of the shared resource without any grant. In another embodiment, an acknowledge and continue command is used to extend all or a subset of the previous grants without the need for additional requests and grants, and their associated overhead. In one embodiment, a traffic to pilot ratio (T/P) is used to allocate a portion of the shared resource, allowing a mobile station flexibility in selecting its transmission format based on T/P.

Scheduled and autonomous transmission and acknowledgement

Techniques are provided to support fast frequency hopping with a code division multiplexed (CDM) pilot in a multi-carrier communication system (e.g., an OFDMA system). Each transmitter (e.g., each terminal) in the system transmits a wideband pilot on all subbands to allow a receiver (e.g., a base station) to estimate the entire channel response at the same time. The wideband pilot for each transmitter may be generated using direct sequence spread spectrum processing and based on a pseudo-random number (PN) code assigned to that transmitter. This allows the receiver to individually identify and recover multiple wideband pilots transmitted concurrently by multiple transmitters. For a time division multiplexed (TDM)/CDM pilot transmission scheme, each transmitter transmits the wideband pilot in bursts. For a continuous CDM pilot transmission scheme, each transmitter continuously transmits the wideband pilot, albeit at a low transmit power level. Any frequency hopping rate may be supported without impacting pilot overhead.

Fast frequency hopping with a code division multiplexed pilot in an OFDMA system

A set of different pilot structures are designed for use in different environments and/or different user behaviours that are expected to occur in a cell. The radio conditions for a user are estimated. Each user is then assigned an area (108A-E) in resource space for its communication, which has a suitable pilot configuration. In one embodiment, the entire resource space is provided with different pilot structures in different parts (110A-D) In advance and allocation of resources to the users are then performed in order to match estimated radio conditions to the provided pilot structure. In another embodiment, allocation is performed first, and then the actual pilot structure is adapted within the allocated resource space area to suit the environmental conditions.

Method and apparatus for allocating a pilot signal adapted to the channel characteristics

There are provided a transmitting/receiving apparatus and method for packet data service in a mobile telecommunication system. To determine the transmission format of packet data between a first format and a second format longer than the first format based on at least one channel state value received from a mobile station, received channel state values are sequentially stored. Then, the differences between all adjacent channel state values are calculated and summed. The sum is compared with a predetermined threshold. If the sum is greater than or equal to the predetermined threshold, the transmission format of the packet data is determined as the first format. If the sum is less than the predetermined threshold, the transmission format of the packet data is determined as the second format.

Transmitting/receiving apparatus and method for packet data service in a mobile telecommunication system

A base station transmission apparatus for transmitting MAC (Medium Access Control) ID (Identification) information indicating a terminal to receive transmission packet data and length information of the transmission packet data in a mobile communication system for high-speed packet transmission, having an encoder for encoding a bit stream indicating the MAC ID information and generating coded symbols; a Walsh cover section for Walsh-covering the coded symbols from the encoder with a Walsh code based on the length information; and a Walsh spreader for spreading the Walsh-covered symbols from the Walsh cover section with a predetermined Walsh code.

Apparatus and method for communicating packet data control channel in a mobile communication system

of EP1306982A method for controlling power of common power control channels from a plurality of base stations in order to control transmission power of a mobile station in a mobile communication system. The power control method comprises receiving, by the mobile station, pilot signals from the base stations and selecting a base station that transmitted a pilot signal having a highest power level; transmitting information indicating a channel condition between the selected base station and the mobile station, from the mobile station to the selected base station; and controlling power of a common power control channel transmitted from the selected base station to the mobile based on the channel condition information received from the selected base station.

Jae-Sung Jang

Papers

Transmitting/receiving apparatus and method for packet data service in a mobile telecommunication system

Apparatus and method for communicating packet data control channel in a mobile communication system

Apparatus and method for controlling power of a common reverse power control channel in a mobile communication system

Vorrichtung und Verfahren zur Regelung der Leistung eines gemeinsamen Rückwärtsleistungsregelungskanals in einem mobilen Kommunikationssystem