Wide area and local network ID transmission for communication systems

Patent metadata

Field	Value
Publication number	US-9356752-B2
Application number	US-94875910-A
Country	US
Kind code	B2
Filing date	Nov 18, 2010
Priority date	Dec 22, 2004
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

The embodiments utilize OFDM symbols to communicate network IDs. The IDs are encoded into symbols utilizing the network IDs as seeds to scramble respective pilots that are then transmitted by utilizing the symbols. The pilots can be structured into a single OFDM symbol and/or multiple OFDM symbols. The single symbol structure for transmitting the network IDs is independent of the number of network ID bits and minimizes frequency offset and Doppler effects. The multiple symbol structure allows a much coarser timing accuracy to be employed at the expense of transmitting additional symbols. Several embodiments employ a search function to find possible network ID candidates from a transmitted symbol and a selection function to find an optimum candidate from a network ID candidate list.

First claim

The invention claimed is:

1. A method for facilitating data communications, comprising:
utilizing at least one orthogonal frequency-division multiplexing (OFDM) symbol structured with at least one pilot respective of a network identification (ID) for communicating the network ID between entities;
calculating a search metric, wherein the search metric comprises an unbiased estimate of total channel energy derived from the pilot;
employing, by a receiving entity, a search process using the search metric to determine network ID candidates based on the calculated search metric;
calculating a selection metric for each network ID candidate, each selection metric having a value; and,
employing a selection process to determine at least one optimum network ID candidate based on the values of the selection metrics.

2. The method of claim 1 further comprising:
employing an OFDM symbol structure with one pilot respective of the network ID per OFDM symbol.

3. The method of claim 1 further comprising:
employing an OFDM symbol structure with pilots respective of the network ID interleaved in at least one OFDM symbol.

4. The method of claim 1 , the entities comprising networks and/or mobile devices.

5. The method of claim 1 further comprising:
constructing the at least one OFDM symbol through utilization of the network ID to facilitate in scrambling the pilot respective of the network ID, the pilot being utilized in the at least one OFDM symbol.

6. The method of claim 5 further comprising:
employing a pseudo-noise (PN) sequence generator, seeded by at least one network ID, to facilitate in scrambling the pilot respective of the network ID.

7. The method of claim 1 , the search metric comprising a metric of an unbiased estimate of total energy, η, of a channel based on

η

(
i
)

⁡

(
n
)

=

∑

k
=
0

5
·
128

-
1

⁢

(

max
⁢

{

s
k

(
i
)

⁡

(
n
)

-

λ
⁢

⁢

w

(
i
)

⁡

(
n
)

,
0

}

)

;

where n is the nth pilot symbol,

w

(
i
)

⁡

(
n
)

=

1

8
·
128

⁢

∑

k
=

7
·
128

14
·
128

-
1

⁢

s
k

(
i
)

 is an interference power spectral density (PSD) energy, and s k (i) is an energy of a kth sample under an ith hypothesis, and λ is a predetermined constant.

8. The method of claim 7 , the search metric with S selection diversity for an interleaved network ID pilot symbol comprising:

η

(
i
)

=

∑

s
=
1

S

⁢

⁢

η

(
i
)

⁡

(
s
)

.

9. The method of claim 1 , the search process comprising:
determining at least one candidate network ID list of the network ID candidates;
determining at least one network ID candidate set from the network ID candidate list according to the search metric; and
determining at least one

Assignees

• Wang Michael Mao
• Vrcelj Bojan
• Mukkavilli Krishna Kiran
• Krishnamoorthi Raghuraman
• Vijayan Rajiv
• Qualcomm Inc

Inventors

• Wang Michael Mao
• Vrcelj Bojan
• Mukkavilli Krishna Kiran
• Krishnamoorthi Raghuraman
• Vijayan Rajiv

Classifications

• H04L5/0007 Primary

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title

• H04L5/0083

  symbol-by-symbol · CPC title

• H04L5/0048 Primary

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04L27/261

  Details of reference signals · CPC title

• H04L5/005

  of common pilots, i.e. pilots destined for multiple users or terminals · CPC title