A method and apparatus for multiplexing reference signals in a predetermined number of Code Division Multiplexing (CDM) groups to balance power across Orthogonal Frequency Division Multiplexing (OFDM) symbols are disclosed. In a wireless communication system, orthogonal sequences used for spreading the reference signals are allocated such that the order of orthogonal sequences allocated to a subcarrier of one CDM group has a predetermined offset with respect to the order of orthogonal sequences allocated to a subcarrier of another CDM group, adjacent to the subcarrier of the one CDM group.

A cellular communication system comprising a plurality of geographically spaced base stations (2) each of which comprises an antenna arrangement (4, 6, 8) per base station sector, each of which antenna arrangements has an antenna element for generating an array of narrow beams (10, 12, 14) covering the sector. Timeslots are simultaneously transmitted over each of the beams so as to generate successive sets of simultaneously transmitted timeslots per sector. The timeslots are each split into multiple orthogonal codes, for example Walsh codes. The communication system additionally comprising a scheduling device (31) for allocating for successive sets of timeslots common overhead channels, including a common pilot channel, which are allocated to the same sub-set of codes of each timeslot in the set. For successive sets of timeslots different data traffic is allocated to the same sub-set of codes of each timeslot in the set. This effectively generates a sector wide antenna beam carrying the common overhead channels and a plurality of narrow teams each of which carry different data traffic. Inter-beam interference is addressed by the application of Adaptive Modulation and Coding and by an inter-beam handoff scheme. The handoff scheme ensures that when an end user equipment is located in a cusp region between adjacent beams the antenna arrangement simultaneously transmits data traffic to that mobile station on at least both of the adjacent beams.

Methods and a system are described for generating a waveform for transmitting data over a channel divided into a plurality of adjacent frequency subcarriers. One method includes receiving a plurality of data bits, each destined for a different receiver of a plurality of receivers. For each received data bit, the method further includes coding the data bit using a unique spreading code of a first set of spreading codes to generate a corresponding group of multiple copies of a data symbol. Additionally, the groups of data symbols, corresponding to the plurality of data bits, are interleaved to generate a sequence of interleaved data symbols, and the sequence of interleaved data symbols is mapped to the plurality of adjacent frequency subcarriers to generate a waveform symbol.

The present disclosure provides an orthogonal codes based code division multiplexing method of performing the code division multiplexing of demodulation reference signals in multiple layers of resource blocks by using orthogonal matrices, the method comprising: changing the order of chips in particular rows of a first orthogonal matrix to obtain a second orthogonal matrix with the changed order of chips; and multiplying the chips in respective rows of the second orthogonal matrix by the demodulation reference signals in corresponding layers of resource blocks correspondingly in the time direction to obtain code division multiplexing signals. The technical scheme of the present disclosure can improve the power jitter situation of downlink signals on the time, thereby the usage efficiency of the power amplifier at the base station side can be improved.

When a plurality of terminals share the same resources in a wireless communication system, and when control information such as acknowledgement/negative acknowledgement (ACK/NAK) information or scheduling information is transmitted, a method of efficiently performing code division multiplexing (CDM) is required to distinguish the plurality of terminals. In particular, it is necessary to develop a method by which a code sequence of CDM can be selected and used according to each cell condition. Provided is a method of forming a signal in a wireless communication system in which a plurality of terminals commonly share frequency and time resources. The method includes the operations of receiving condition information in a cell; selecting one of a plurality of time domain orthogonal sequences having different lengths, according to the condition information; and allocating the selected time domain orthogonal sequence to a control signal symbol block.

A receiver in a CDMA system comprises a front end processor that generates a combined signal per source. A symbol estimator processes the combined signal to produce symbol estimates. An S-Matrix Generation module refines these symbol estimates based on the sub channel symbol estimates. An interference canceller is configured for cancelling interference from at least one of the plurality of received signals for producing at least one interference-cancelled signal.

A terminal apparatus is disclosed wherein even in a case of applying SU-MIMO and MU-MIMO at the same time, the inter-sequence interference in a plurality of pilot signals used by the same terminal can be suppressed to a low value, while the inter-sequence interference in pilot signal between terminals can be reduced. In this terminal apparatus: a pilot information deciding unit decides, based on allocation control information, Walsh sequences of the respective ones of first and second stream groups at least one of which includes a plurality of streams; and a pilot signal generating unit forms a transport signal by using the decided Walsh sequences to spread the streams included in the first and second stream groups. During this, Walsh sequences orthogonal to each other are established in the first and second stream groups, and users are allocated on a stream group-by-stream group basis.

Various embodiments provide for the management of wireless resources, which can reduce call blocking by allowing high priority services, under suitable conditions, to use resources allocated to low priority services. Thus high priority services can pre-empt the usage of wireless resources by low priority services. This has the advantage of reducing call blocking for high priority calls, while permitting low priority calls to have more access to radio resources than conventional systems with the same call blocking rate. Thus a base station can implement a preemption mechanism that would reclaim Walsh Code and Forward Power resources from an active Supplemental Channel (SCH) burst in order to accommodate incoming Fundamental Channel (FCH) requests.

[Object] To provide a transmission apparatus, reception apparatus, and information processing method which enable a wireless device to carry out wireless transmission with less power consumption. [Solution] A transmission apparatus includes: a communication unit configured to transmit a transmission signal from the transmission apparatus to a reception apparatus via wireless communication; and a signal processing unit configured to generate the transmission signal in which transmission information is spread by using a spreading code selected according to identification information of the transmission apparatus, in order to enable the reception apparatus to acquire the identification information on the basis of an estimation result of the spreading code used for the transmission signal.

Methods, systems, and devices are described for orthogonal modulation of signals using maximal length sequences and Hadamard transforms. Modulation symbols to be transmitted are arranged into sequences indexed from 1 to 2.sup.n1 for some integer n. A constant is added to the beginning of each sequence, which is then multiplied by a Hadamard matrix of size 2.sup.n2.sup.n. The resulting sequences will be orthogonal and will have a first value of zero. The first value is discarded, and the sequence are reordered and associated with m-sequences. The signal is then transmitted. A cyclic prefix may also be transmitted. Upon receiving the transmission, a receiver may discard the cyclic prefix or use it for channel equalization. The receiver may then reorder the received signal, insert a zero, apply the 2.sup.n2.sup.n Hadamard transform, discard the zero, and order the sequences again according to the index to retrieve the data.