Motorola Mobility LLC

Google Inc.

Motorola Corporation

Masaya Fukuta

Hidenori Akita

Hiroshi Hayashi

Vijay Nangia

Kevin Lynn Baum

Robert T Love

Brian Keith Classon

Kenneth Anderson Stewart

A method and apparatus is provided for transmitting an orthogonal frequency domain multiple access (OFDMA) signal including a synchronization channel signal transmitted including a plurality of sequence elements interleaved in time and frequency. The synchronization channel signal sequence elements enable an initial acquisition and cell search method with low computational load by providing predetermined time domain symmetry for common sequence elements in OFDMA symbol periods for OFDMA symbol timing detection and frequency error detection in an OFDMA system supporting multiple system bandwidths, both synchronized and un-synchronized systems, a large cell index and an OFDMA symbol structure with both short and long cyclic prefix length.

Method and apparatus for interleaving sequence elements of an OFDMA synchronization channel

The GCL sequence index of each cell/sector is assigned so that a difference of the indices between adjacent cells/sectors is more than N, where N&#x2267;1. During GCL index detection, the adjacent N&#x2212;1 indices of an index with the largest magnitude can be deleted from handoff candidate cell indices.

Method and apparatus for fast cell search

A method and apparatus for transmitting a primary and secondary synchronization channel is provided herein. During operation a transmitter will transmit a primary synchronization channel (P-SCH) in a subframe and a secondary synchronization channel (S-SCH) in the subframe. The S-SCH is modulated by a complex exponential wave and scrambled with a scrambling code. In certain embodiments of the present invention the P-SCH comprises a GCL sequence or a Zadoff-Chu sequence and the scrambling code is based on the GCL sequence index of the P-SCH.

A method and apparatus for fast cell search based on a chirp reference signal transmission is disclosed herein. A primary synchronization channel (P-SCH) and two secondary synchronization channels (S-SCHand S-SCH) will be utilized. S-SCHwill comprise a reference sequence having a first index value and S-SCHwill comprise a reference sequence having a second index value. S-SCHand S-SCHwill be scrambled with a first and a second scrambling code, respectively. The second scrambling code will be based on the first index value.

Reference sequence construction for fast cell search

Frequency hopping in an IFDMA system takes place by utilizing a time-varying IFDMA modulation code. In particular, a modulator receives a symbol stream and a user specific IFDMA modulation code (b(t)). The output of the modulator comprises a signal (x(t)) existing at certain frequencies, or subcarriers. The actual subcarriers that signal x(t) utilizes is dependent upon the repetition of the symbol blocks and the particular IFDMA modulation code utilized.

Frequency-hopped IFDMA communication system

A method and apparatus is provided for transmitting an orthogonal frequency domain multiple access (OFDMA) signal including a synchronization channel signal transmitted within a localized portion of a bandwidth of the OFDMA signal (), the synchronization channel signal having predetermined time domain symmetry within the localized portion of the bandwidth () and including information for providing at least partial cell identification information (). The synchronization channel signal enables an initial acquisition and cell search method with low computational load which provides OFDMA symbol timing detection and frequency error detection () and frame boundary detection and cell specific information detection () in an OFDMA system supporting multiple system bandwidths, both synchronized and un-synchronized systems, a large cell index and an OFDMA symbol structure with both short and long cyclic prefix length.

Method and apparatus for initial acquisition and cell search for an OFDMA system

A method and apparatus for fast cell search based on a chirp reference signal transmission is disclosed herein. A primary synchronization channel (P-SCH) and two secondary synchronization channels (S-SCHand S-SCH) will be utilized. S- SCHwill comprise a reference sequence having a first index value and S-SCHwill comprise a reference sequence having a second index value. S-SCHand S- SCHwill be scrambled with a first and a second scrambling code, respectively. The second scrambling code will be based on the first index value.

A method and apparatus is provided for transmitting an orthogonal frequency domain multiple access (OFDMA) signal including a synchronization channel signal transmitted including a plurality of sequence elements interleaved in time and frequency (). The synchronization channel signal sequence elements enable an initial acquisition and cell search method with low computational load by providing predetermined time domain symmetry () for common sequence elements in OFDMA symbol periods () for OFDMA symbol timing detection and frequency error detection in an OFDMA system supporting multiple system bandwidths, both synchronized and un-synchronized systems, a large cell index and an OFDMA symbol structure with both short and long cyclic prefix length.

A method and apparatus is provided for transmitting an orthogonal frequency domain multiple access (OFDMA) signal including a synchronization channel signal transmitted within a localized portion of a bandwidth of the OFDMA signal (), the synchronization channel signal having predetermined time domain symmetry within the localized portion of the bandwidth (). The synchronization channel signal enables an initial acquisition and cell search method with low computational load which provides OFDMA symbol timing detection and frequency error detection by differential processing of sequence elements of the synchronization channel signal () and frame boundary detection and cell specific information detection () in an OFDMA system supporting multiple system bandwidths, both synchronized and un-synchronized systems, a large cell index and an OFDMA symbol structure with both short and long cyclic prefix length.

Method and apparatus for a synchronization channel in an OFDMA system

A method and system for adaptive control of sub-carriers is useful for increasing frequency diversity gain to improve bit error rate performance in an Interleaved Frequency Division Multiple Access (IFDMA) system. The method includes selecting a combination of a Repetition Factor (RF) and a repetition block size (Q), from possible combinations of a RF and a Q, based on a number of users (N) (step). A Spreading Factor (SF), Forward Error Correction (FEC) coding rate (R), or modulation order (M) based on the Nis then determined (step). Control signals are then provided based on the RF and Q, and based on the SF, R, or M (step).

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Meguro-ku, Japan

Masaya Fukuta