Abstract:
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-SCH1 and S-SCH2) will be utilized. S-SCH1 will comprise a reference sequence having a first index value and S-SCH2 will comprise a reference sequence having a second index value. S-SCH1 and S-SCH2 will be scrambled with a first and a second scrambling code, respectively. The second scrambling code will be based on the first index value.
Abstract:
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.
Abstract:
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 (818), the synchronization channel signal having predetermined time domain symmetry within the localized portion of the bandwidth (816) and including information for providing at least partial cell identification information (812). 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 (1112) and frame boundary detection and cell specific information detection (1114) 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.
Abstract:
Frequency hopping in an IFDMA system takes place by utilizing a time-varying IFDMA modulation code. In particular, a modulator (102) receives a symbol stream and a user specific IFDMA modulation code (b^[igrave](t)) (112). The output of the modulator comprises a signal (X^i(t)) existing at certain frequencies, or subcarriers (114). The actual subcarriers that signal X^i(t) utilizes is dependent upon the repetition of the symbol blocks and the particular IFDMA modulation code utilized (108).
Abstract:
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.
Abstract:
A method and apparatus for using both D-FDMA and L-FDMA within a same frequency band is provided herein. The proposed technique scatters the sub-carriers of each D-FDMA user to a frequency band utilized by L-FDMA communications without separating the total band into exclusive D-FDMA and L-FDMA sub-bands. The L-FDMA users are assigned to the gap of the D-FDMA sub-carriers. Therefore, frequency diversity gain of D-FDMA by the proposed method is larger than if D-FDMA and L-FDMA sub-bands were created.
Abstract:
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 (Nu) (step 1405). A Spreading Factor (SF), Forward Error Correction (FEC) coding rate (R), or modulation order (M) based on the Nu is then determined (step 1410). Control signals are then provided based on the RF and Q, and based on the SF, R, or M (step 1415).
Abstract:
Reference sequences are constructed from distinct "classes" of GCL sequences that have an optimal cyclic cross correlation property. The fast cell search method disclosed detects the "class indices" with simple processing. In a system deployment that uniquely maps sequences of certain class indices along with a circular shift amount in time domain to certain cells/cell IDs, the identification of a sequence index, and its circular shift will therefore provide an identification of the cell ID.
Abstract:
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 intereleaved in time and frequency (610, 640). The synchronization channel signal sequence elements enable an initial acquisition and cell search method with low computational load by providing predetermined time domain symmetry (702, 704) for common sequence elements in OFDMA symbol periods (620, 660) 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.
Abstract:
Reference sequences are constructed from distinct "classes" of GCL sequences that have an optimal cyclic cross correlation property. The fast cell search method disclosed detects the "class indices" with simple processing. In a system deployment that uniquely maps sequences of certain class indices along with a circular shift amount in time domain to certain cells/cell IDs, the identification of a sequence index, and its circular shift will therefore provide an identification of the cell ID.